US sanctions on Iran began in 1979, following the Iranian hostage crisis. The first sanctions banned Iranian products other than small gifts, informational materials, food, and "some carpets," according to Reuters.
The UN and EU have since come down with sanctions themselves and broadened their scope. Here's a recap of the sanctions Iran faces now.
Oil and trade
In 1995 President Clinton issued an executive order that banned US companies from investing in Iranian oil and gas or from trading with Iran, according to Reuters. Roughly 20 Iranian petroleum and petrochemical companies were identified as being under Iranian government control and off limits for US companies.
In 2010, the US imposed penalties on foreign companies providing Iran with more than $5 million worth of refined petroleum a year effectively banning them from doing business in the US as well. Other sanctions in 2010 put the squeeze on energy companies.
Venezuela's decision to trade with Iran prompted American sanctions on oil companies in Latin America's oil powerhouse as well.
In March 2008, the UN requested that countries inspect cargo carried to and from Iran in planes and ships owned or operated by IranAir Cargo and the Islamic Republic of Iran Shipping Line. It also expanded a partial ban on civilian and military trade "to cover sales of all such technology to Iran," according to Reuters.
European Union measures approved in 2010 bar cargo flights to and from Iran. Later that year, the EU toughened its sanctions on Iran, including a ban on business partnerships with Iranian businesses tied to the oil and gas industries and on providing insurance to the Iranian government.
The 2010 sanctions also forbade the sale and supply of energy equipment and technology used in the refinement and exploration of natural gas.
The financial system
The US imposed sanctions on three Iranian banks in October 2007 and expanded sanctions to several other Iranian banks over time — more than 20 by 2011.
In March 2008, the UN called on countries to "exercise vigilance" over the activities of financial institutions based in Iran, particularly Bank Melli and Bank Saderat.
A 2010 law further strengthened US sanctions on Iranian banks. It also imposed penalties on companies that provide large amounts of petroleum to Iran and barred foreign banks from doing business in the US if they also do business with Iranian banks or Iran's Revolutionary Guards. It specifically sanctioned Bank Refah in 2011 for its role in Iran's purchase of millions of dollars worth of tanks and missiles.
EU sanctions were expanded in 2011 to include over 100 more companies and people already under EU sanctions, including banks that do business with Iran and many companies owned or run by the Islamic Republic of Iran Shipping Lines.
Arms embargo
The Security Council banned the export of Iranian arms to other countries in March 2007. The EU barred the import and export of arms and equipment that could help with uranium enrichment.
Nuclear programme
UN sanctions in December 2006 blocked the import and export from Iran of "sensitive nuclear materials and equipment" and told Iran to "without further delay, suspend the following proliferation sensitive nuclear activities: all enrichment-related and reprocessing activities, including research and development; and work on all heavy-water related projects, including the construction of a research reactor moderated by heavy water." It gave Iran a 60-day deadline, which was ignored.
The European Union has imposed visa bans on several Iranian senior officials, including several nuclear experts.
Assets
The UN Security Council first joined the US in freezing assets in December 2006 with a freeze on assets belonging to Iranian individuals and companies linked to the country's nuclear programme.
It expanded the freeze to 28 more people, companies, and groups in March 2007, including the state run bank, Bank Sepah, as well as firms controlled by the Iranian Revolutionary Guards. The scope was expanded again in March 2008 to another 13 people and 12 companies.
