The 1979 oil crisis, also known as the 1979 Oil Shock or Second Oil Crisis, was an
energy crisis
An energy crisis or energy shortage is any significant bottleneck in the supply of energy resources to an economy. In literature, it often refers to one of the energy sources used at a certain time and place, in particular, those that supply n ...
caused by a drop in
oil production
Petroleum is a fossil fuel that can be drawn from beneath the earth's surface. Reservoirs of petroleum was formed through the mixture of plants, algae, and sediments in shallow seas under high pressure. Petroleum is mostly recovered from oil dri ...
in the wake of the
Iranian Revolution
The Iranian Revolution ( fa, انقلاب ایران, Enqelâb-e Irân, ), also known as the Islamic Revolution ( fa, انقلاب اسلامی, Enqelâb-e Eslâmī), was a series of events that culminated in the overthrow of the Pahlavi dyna ...
. Although the
global oil supply only decreased by approximately four percent,
the oil markets' reaction raised the
price of crude oil drastically over the next 12 months, more than doubling it to . The sudden increase in price was connected with fuel shortages and long lines at
gas stations
A filling station, also known as a gas station () or petrol station (), is a facility that sells fuel and engine lubricants for motor vehicles. The most common fuels sold in the 2010s were gasoline (or petrol) and diesel fuel.
Gaso ...
similar to the
1973 oil crisis.
In 1980, following the onset of the
Iran–Iraq War
The Iran–Iraq War was an armed conflict between Iran and Ba'athist Iraq, Iraq that lasted from September 1980 to August 1988. It began with the Iraqi invasion of Iran and lasted for almost eight years, until the acceptance of United Nations S ...
, oil production in Iran fell drastically.
Iraq's oil production also dropped significantly, triggering
economic recessions worldwide. Oil prices did not return to pre-crisis levels until the mid-1980s.
Oil prices after 1980 began a steady
decline over the next 20 years, except for a brief uptick during the
Gulf War
The Gulf War was a 1990–1991 armed campaign waged by a Coalition of the Gulf War, 35-country military coalition in response to the Iraqi invasion of Kuwait. Spearheaded by the United States, the coalition's efforts against Ba'athist Iraq, ...
, which then reached a 60% fall-off in the 1990s.
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
,
Nigeria
Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...
, and
Venezuela
Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...
's major oil exporters expanded their production during this time. The
Soviet Union
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...
became the largest oil producer in the world, and oil from the
North Sea
The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea, epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the ...
and
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S. ...
flooded the market.
Iran
In November 1978, a strike consisting of 37,000 workers at Iran's nationalized oil refineries reduced production from per day to about .
Foreign worker
Foreign workers or guest workers are people who work in a country other than one of which they are a citizen. Some foreign workers use a guest worker program in a country with more preferred job prospects than in their home country. Guest worke ...
s left the country. However, by bringing navy personnel into crude oil production operations, the government fixed short-term disruptions and by end of November the output came back to almost normal level.
On January 16, 1979, the
Shah of Iran
This is a list of monarchs of Persia (or monarchs of the Iranic peoples, in present-day Iran), which are known by the royal title Shah or Shahanshah. This list starts from the establishment of the Medes around 671 BCE until the deposition of th ...
,
Mohammad Reza Pahlavi, and his wife,
Farah Pahlavi
Farah Pahlavi ( fa, فرح پهلوی, née Farah Diba ( fa, فرح دیبا, label=none); born 14 October 1938) is the widow of the last Shah of Iran, Mohammad Reza Pahlavi, and was successively Queen and Empress ('' Shahbanu'') of Iran fro ...
, left Iran at the behest of Prime Minister
Shapour Bakhtiar, who sought to calm the situation.
After the departure of the Shah,
Ayatollah
Ayatollah ( ; fa, آیتالله, āyatollāh) is an honorific title for high-ranking Twelver Shia clergy in Iran and Iraq that came into widespread usage in the 20th century.
Etymology
The title is originally derived from Arabic word p ...
Khomeini
Ruhollah Khomeini, Ayatollah Khomeini, Imam Khomeini ( , ; ; 17 May 1900 – 3 June 1989) was an Iranian political and religious leader who served as the first supreme leader of Iran from 1979 until his death in 1989. He was the founder of ...
became the new leader of
Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
.
Effects
Other OPEC members
The rise in oil prices benefited a few members of the Organization of Petroleum-Exporting Countries (
OPEC), which made record profits. Under the new Iranian government, oil exports later resumed but production was inconsistent and at a lower volume, further raising prices.
Saudi Arabia
Saudi Arabia, officially the Kingdom of Saudi Arabia (KSA), is a country in Western Asia. It covers the bulk of the Arabian Peninsula, and has a land area of about , making it the fifth-largest country in Asia, the second-largest in the A ...
and other OPEC nations, under the presidency of
Mana Al Otaiba
Mana Al Otaiba (مانع العتيبة المرر) (born 15 May 1946) to Saeed Al Otaiba in Abu Dhabi in the United Arab Emirates. Al Otaiba is the former Minister of Petroleum and Mineral Resources of the United Arab Emirates under the presid ...
, increased production to offset most of the decline, and by early 1979 the overall loss in worldwide production was roughly four percent.
The war between Iran and Iraq in 1980 caused a further 7 percent drop in worldwide production and OPEC production was surpassed by other exporters such as the United States as its member nations were divided amongst themselves. Saudi Arabia, a "
swing producer A swing producer or swing supplier is a supplier or a close oligopolistic group of suppliers of any commodity, controlling its global deposits and possessing large spare production capacity. A swing producer is able to increase or decrease commodit ...
", tried to gain back the market share after 1985, increasing production and causing downward pressure on prices, making high-cost oil production facilities less profitable.
United States
The oil crisis had a mixed impact on the United States. Some regions of the country are oil-producing regions, and other regions are oil-consuming.
Richard Nixon
Richard Milhous Nixon (January 9, 1913April 22, 1994) was the 37th president of the United States, serving from 1969 to 1974. A member of the Republican Party, he previously served as a representative and senator from California and was ...
imposed
price controls on domestic oil. Gasoline controls were repealed, but controls on domestic US oil remained.
The
Jimmy Carter
James Earl Carter Jr. (born October 1, 1924) is an American politician who served as the 39th president of the United States from 1977 to 1981. A member of the Democratic Party, he previously served as the 76th governor of Georgia from 1 ...
administration began a phased
deregulation of oil prices on April 5, 1979, when the average
price of crude oil was US. Starting with the Iranian revolution, the price of crude oil rose to over the next 12 months (its all-time highest
real price
In economics, nominal value is measured in terms of money, whereas real value is measured against goods or services. A real value is one which has been adjusted for inflation, enabling comparison of quantities as if the prices of goods had not c ...
until March 3, 2008).
Deregulating domestic oil price controls allowed U.S. oil output to rise sharply from the large
Prudhoe Bay
Prudhoe Bay is a census-designated place (CDP) located in North Slope Borough in the U.S. state of Alaska. As of the 2010 census, the population of the CDP was 2,174 people, up from just five residents in the 2000 census; however, at any give ...
fields, while oil imports fell sharply.
Although not directly related,
the near-disaster at Three Mile Island on March 28, 1979, also increased anxiety about energy policy and availability. Due to memories of
the oil shortage in 1973, motorists soon began panic buying, and long lines appeared at gas stations, as they had six years earlier. The average vehicle of the time consumed between two and three liters (about 0.5–0.8 gallons) of
gasoline
Gasoline (; ) or petrol (; ) (see ) is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines (also known as petrol engines). It consists mostly of organi ...
an hour while idling, and it was estimated that Americans wasted up to of oil per day idling their engines in the lines at
gas stations.
The amount of oil sold in the United States in 1979 was only 3.5 percent less than the record set for oil sold the previous year.
[
] A telephone poll of 1,600 American adults conducted by the Associated Press and NBC News and released in early May 1979 found that only 37 percent of Americans thought the energy shortages were real, nine percent were not sure, and 54 percent thought the energy shortages were a hoax.
Many politicians proposed gas
rationing
Rationing is the controlled distribution of scarce resources, goods, services, or an artificial restriction of demand. Rationing controls the size of the ration, which is one's allowed portion of the resources being distributed on a particular ...
. One such proponent was
Harry Hughes
Harry Roe Hughes (November 13, 1926 – March 13, 2019) was an American politician from the Democratic Party who served as the 57th Governor of Maryland from 1979 to 1987.
Early life and family
Hughes was born in Easton, Maryland, the s ...
,
Governor of Maryland
The Governor of the State of Maryland is the head of government of Maryland, and is the commander-in-chief of the state's National Guard units. The Governor is the highest-ranking official in the state and has a broad range of appointive powers ...
, who proposed
odd-even rationing (only people with an odd-numbered license plate could purchase gas on an odd-numbered day), as was used during the
1973 Oil Crisis. Several states implemented odd-even gas rationing, including
California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
,
Pennsylvania
Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...
,
New York,
New Jersey
New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...
,
Oregon
Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. T ...
, and
Texas
Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...
. Coupons for gasoline rationing were printed but were never actually used during the 1979 crisis.
On July 15, 1979, President Carter outlined his plans to reduce oil imports and improve energy efficiency in his "Crisis of Confidence" speech (sometimes known as the "
malaise" speech). In the speech, Carter encouraged citizens to do what they could to reduce their use of energy. He had already installed water tank heating solar panels on the roof of the
White House
The White House is the official residence and workplace of the president of the United States. It is located at 1600 Pennsylvania Avenue NW in Washington, D.C., and has been the residence of every U.S. president since John Adams in ...
and a
wood-burning stove
A wood-burning stove (or wood burner or log burner in the UK) is a heating or cooking appliance capable of burning wood fuel and wood-derived biomass fuel, such as sawdust bricks. Generally the appliance consists of a solid metal (usually cast ...
in the living quarters. However, the panels were removed in 1986, reportedly for roof maintenance, during the administration of his successor,
Ronald Reagan.
Carter's speech argued the oil crisis was "the moral equivalent of war". In November 1979, Iranian revolutionaries seized the American Embassy, and Carter imposed an embargo on Iranian oil. In January 1980, he issued the
Carter Doctrine
The Carter Doctrine was a policy proclaimed by President of the United States Jimmy Carter in his State of the Union Address on January 23, 1980, which stated that the United States would use military force, if necessary, to defend its national i ...
, declaring: "An attempt by any outside force to gain control of the
Persian Gulf
The Persian Gulf ( fa, خلیج فارس, translit=xalij-e fârs, lit=Gulf of Fars, ), sometimes called the ( ar, اَلْخَلِيْجُ ٱلْعَرَبِيُّ, Al-Khalīj al-ˁArabī), is a mediterranean sea in Western Asia. The bod ...
region will be regarded as an assault on the vital interests of the United States." Additionally, as part of his administration's efforts at deregulation, Carter proposed removing price controls that had been imposed by the
Richard Nixon
Richard Milhous Nixon (January 9, 1913April 22, 1994) was the 37th president of the United States, serving from 1969 to 1974. A member of the Republican Party, he previously served as a representative and senator from California and was ...
administration before the 1973 crisis. Carter agreed to remove price controls in phases. They were finally dismantled in 1981 under Reagan. Carter also said he would impose a windfall profit tax on oil companies.
[
] While the regulated price of domestic oil was kept to $6 a barrel, the world market price was $30.
In 1980, the U.S. government established the
Synthetic Fuels Corporation
The Synthetic Fuels Corporation (SFC or Synfuels Corporation) was a U.S. government-funded corporation established in 1980 by the Energy Security Act (ESA) to create a financial bridge for the development and construction of commercial synthetic ...
to produce an alternative to imported fossil fuels.
When the price of
West Texas Intermediate
West Texas Intermediate (WTI) is a grade or mix of crude oil; the term is also used to refer to the spot price, the futures price, or assessed price for that oil. In colloquial usage, WTI usually refers to the WTI Crude Oil futures contract tr ...
crude oil increased 250 percent between 1978 and 1980, the oil-producing areas of Texas, Oklahoma, Louisiana, Colorado, Wyoming, and Alaska began experiencing an economic boom and population inflows.
According to one study, individuals who were between the ages of 15 and 18 during the 1979 oil crisis were substantially less likely to use cars once they were in their mid-30s.
Other oil-consuming nations
In response to the high oil prices of the 1970s, industrial nations took steps to reduce their dependence on the Organization of Petroleum-Exporting Countries (OPEC) oil.
[ Electric utilities worldwide switched from oil to coal, natural gas, or nuclear power. National governments initiated multibillion-dollar research programs to develop alternatives to oil and commercial exploration developed major non-OPEC oilfields in Siberia, Alaska, North Sea, and the Gulf of Mexico. By 1986, daily worldwide demand for oil dropped by 5 million barrels but, non-OPEC production rose by an even-larger amount. Consequently, OPEC's market share reduced from 50 percent in 1979 to 29 percent in 1985.
]
Automobile fuel economy
At the time, Detroit's "Big Three" automakers (Ford
Ford commonly refers to:
* Ford Motor Company, an automobile manufacturer founded by Henry Ford
* Ford (crossing), a shallow crossing on a river
Ford may also refer to:
Ford Motor Company
* Henry Ford, founder of the Ford Motor Company
* Ford F ...
, Chrysler, GM) were marketing downsized full-sized automobiles like the Chevrolet Caprice
The Chevrolet Caprice is a full-sized automobile produced by Chevrolet in North America for the 1965 to 1996 model years. Full-size Chevrolet sales peaked in 1965 with over a million sold. It was the most popular car in the U.S. in the 1960s ...
, the Ford LTD Crown Victoria
The Ford LTD Crown Victoria is a line of full-size cars that was manufactured and marketed by Ford from the 1980 to 1991 model years. Deriving its name from the Ford Fairlane coupe of 1955–1956, the LTD Crown Victoria served as the flagship ...
and the Dodge St. Regis which met the CAFE
A coffeehouse, coffee shop, or café is an establishment that primarily serves coffee of various types, notably espresso, latte, and cappuccino. Some coffeehouses may serve cold drinks, such as iced coffee and iced tea, as well as other non-caf ...
fuel economy mandates passed in 1978. Detroit's response to the growing popularity of imported compacts like the Toyota Corolla and the Volkswagen Rabbit
The Volkswagen Golf () is a compact car/small family car (C-segment) produced by the German automotive manufacturer Volkswagen since 1974, marketed worldwide across eight generations, in various body configurations and under various nameplates ...
was the Chevrolet Citation
The Chevrolet Citation is a range of compact cars that was produced by the Chevrolet division of General Motors. The first Chevrolet sold with front-wheel drive, a single generation of the Citation was sold from the 1980 to 1985 model years. The s ...
and the Ford Fairmont
The Ford Fairmont is a model line of compact cars that was manufactured by Ford from the 1978 to 1983 model years. The successor of the Ford Maverick, the Fairmont marked the third generation of compact sedans sold by Ford in North America and ...
. Ford replaced the Ford Pinto
The Ford Pinto is a subcompact car that was manufactured and marketed by Ford Motor Company in North America from 1971 until 1980 model years. The Pinto was the first subcompact vehicle produced by Ford in North America.
The Pinto was marketed ...
with the Ford Escort and Chrysler, on the verge of bankruptcy, introduced the Dodge Aries K. GM was having unfavorable market reactions to the Citation and introduced the Chevrolet Corsica and Chevrolet Beretta in 1987 which sold better. GM also replaced the Chevrolet Monza
The Chevrolet Monza is a subcompact automobile produced by Chevrolet for the 1975 through 1980 model years. The Monza is based on the Chevrolet Vega, sharing its wheelbase, width, and standard inline-four engine. The car was designed to accommoda ...
, introducing the 1982 Chevrolet Cavalier
The Chevrolet Cavalier is a line of compact cars produced by Chevrolet. Serving as the replacement of the Chevrolet Monza, the Cavalier was the second Chevrolet model line to adopt front-wheel drive. Three versions of the Cavalier have been so ...
which was better received. Ford experienced a similar market rejection of the Fairmont and introduced the front-wheel-drive Ford Tempo
The Ford Tempo and its Mercury counterpart the Topaz, are compact cars produced by the Ford Motor Company for model years 1984 to 1994. They were the downsized successors to the Ford Fairmont and Mercury Zephyr respectively. The Tempo and Topa ...
in 1984.
Detroit was not well prepared for the sudden rise in fuel prices, and imported brands (primarily the Asian models, which were mass-marketed and had a lower manufacturing cost as opposed to British
British may refer to:
Peoples, culture, and language
* British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies.
** Britishness, the British identity and common culture
* British English, ...
and West German
West Germany is the colloquial term used to indicate the Federal Republic of Germany (FRG; german: Bundesrepublik Deutschland , BRD) between its formation on 23 May 1949 and the German reunification through the accession of East Germany on 3 O ...
brands). Moreover, the rising value of the Deutsche mark and British pound resulted in the transition to the rise of Japanese manufacturers as they were able to export their product from Japan at a lower cost, resulting in profitable gains (despite accusations of price dumping
Predatory pricing is a pricing strategy, using the method of undercutting on a larger scale, where a dominant firm in an industry will deliberately reduce the prices of a product or service to loss-making levels in the short-term. The aim is th ...
), and were now more widely available in North America and developing a loyal customer base.
A year after the 1979 Iranian Revolution, Japanese manufacturers surpassed Detroit's production totals, becoming first in the world. Indeed, the share of Japanese cars in U.S. auto purchases rose from 9 percent in 1976 to 21 percent in 1980. Japanese exports would later displace the automotive market once dominated by lower-tier European manufacturers (Renault
Groupe Renault ( , , , also known as the Renault Group in English; legally Renault S.A.) is a French multinational automobile manufacturer established in 1899. The company produces a range of cars and vans, and in the past has manufacture ...
, Fiat, Opel, Peugeot
Peugeot (, , ) is a French brand of automobiles owned by Stellantis.
The family business that preceded the current Peugeot companies was founded in 1810, with a steel foundry that soon started making hand tools and kitchen equipment, and the ...
, MG, Triumph
The Roman triumph (Latin triumphus) was a celebration for a victorious military commander in ancient Rome. For later imitations, in life or in art, see Trionfo. Numerous later uses of the term, up to the present, are derived directly or indirectl ...
, Citroen). Some would declare bankruptcy (e.g. Triumph, Simca
Simca (; Mechanical and Automotive Body Manufacturing Company) was a French automaker, founded in November 1934 by Fiat S.p.A. and directed from July 1935 to May 1963 by Italian Henri Pigozzi. Simca was affiliated with Fiat and, after Simca bough ...
) or withdraw from the U.S. market, especially in the wake of grey market
A grey market or dark market (sometimes confused with the similar term " parallel market") is the trade of a commodity through distribution channels that are not authorized by the original manufacturer or trade mark proprietor. Grey market pr ...
automobiles or the inability of the vehicle to meet DOT requirements (from emission requirements to automotive lighting). Many imported brands utilized fuel-saving technologies such as fuel injection and multi-valve engines over the common use of carburetors. The overall fuel economy of cars in the United States increased from about 15 miles per gallon (mpg) in 1979 to 18 mpg by 1985 and 20 mpg by 1990. This was one factor leading to the subsequent 1980s oil glut
The 1980s oil glut was a serious surplus of crude oil caused by falling demand following the 1970s energy crisis. The world price of oil had peaked in 1980 at over US$35 per barrel (equivalent to $ per barrel in dollars, when adjusted for inf ...
.
See also
*Energy crisis
An energy crisis or energy shortage is any significant bottleneck in the supply of energy resources to an economy. In literature, it often refers to one of the energy sources used at a certain time and place, in particular, those that supply n ...
*Energy diplomacy Energy diplomacy is a form of diplomacy, and a subfield of international relations. It is closely related to its principal, foreign policy, and to overall national security, specifically energy security. Energy diplomacy began in the first half of t ...
*Iran hostage crisis
On November 4, 1979, 52 United States diplomats and citizens were held hostage after a group of militarized Iranian college students belonging to the Muslim Student Followers of the Imam's Line, who supported the Iranian Revolution, took over ...
*1979 world oil market chronology
Events
January
* January 1
** United Nations Secretary-General Kurt Waldheim heralds the start of the ''International Year of the Child''. Many musicians donate to the ''Music for UNICEF Concert'' fund, among them ABBA, who write the song ...
*1980s oil glut
The 1980s oil glut was a serious surplus of crude oil caused by falling demand following the 1970s energy crisis. The world price of oil had peaked in 1980 at over US$35 per barrel (equivalent to $ per barrel in dollars, when adjusted for inf ...
*2000s energy crisis
From the mid-1980s to September 2003, the inflation-adjusted price of a barrel of crude oil on NYMEX was generally under US$25/barrel in 2008 dollars. During 2003, the price rose above $30, reached $60 by 11 August 2005, and peaked at $147. ...
*Hubbert peak theory
The Hubbert peak theory says that for any given geographical area, from an individual oil-producing region to the planet as a whole, the rate of petroleum production tends to follow a bell-shaped curve. It is one of the primary theories on peak ...
* Carless days in New Zealand
References
Further reading
*
* Lesch, David W. ''1979: The Year That Shaped The Modern Middle East'' (2001
excerpt
* Odell, Peter R. ''Oil and gas: crises and controversies 1961-2000'' (2001
online
* Odell, Peter R. ''Oil and world power : background to the oil crisis'' (1974
online
* Painter, David S. (2014) "Oil and geopolitics: The oil crises of the 1970s and the cold war." ''Historical Social Research/Historische Sozialforschung'' (2014): 186–208.
online
* Randall, Stephen J. ''United States foreign oil policy since World War I: For profits and security'' (Montreal: McGill-Queen's Press-MQUP, 2005).
*
{{DEFAULTSORT:1979 Energy Crisis
Energy crisis
An energy crisis or energy shortage is any significant bottleneck in the supply of energy resources to an economy. In literature, it often refers to one of the energy sources used at a certain time and place, in particular, those that supply n ...
Energy crises
History of the petroleum industry
Petroleum politics
Petroleum economics
Presidency of Jimmy Carter
Energy crisis
An energy crisis or energy shortage is any significant bottleneck in the supply of energy resources to an economy. In literature, it often refers to one of the energy sources used at a certain time and place, in particular, those that supply n ...
Embargoes
Iranian Revolution