Iran's nuclear program has been the subject of contention with the West since 2006 over suspicions of its intentions. The UN Security Council imposed sanctions against select companies linked to the nuclear program, thus furthering the country's economic isolation. The economic effects of sanctions have been severe. Sanctions notably bar nuclear, missile and many military exports to Iran and target investments in oil, gas and petrochemicals, exports of refined petroleum products, as well as the Islamic Revolutionary Guard Corps, banks, insurance, financial transactions and shipping. In 2012 the European Union tightened its own sanctions by joining the three decade-old US oil embargo against Iran. In 2015, Iran and the P5+1 reached a deal on the nuclear program that will remove the main sanctions by early 2016. Even though Iran can trade in its own currency some problems subsist mainly due to the fact that it cannot transact in US dollars freely.