In 1996 the U.S. Congress passed the Iran Sanctions Act (ISA), which authorized the imposition of sanctions against companies that agreed to invest more than $20 million in the Iranian petroleum or petrochemical sector. In fact, several companies made or agreed to make investments in Iranian oil and gas fields after passage of the ISA, but successive U.S. Presidents declined to impose sanctions against them. Earlier this year, increasing frustration at the failure to impose sanctions, coupled with increasing concerns about Iran generally, led the U.S. House of Representatives and the U.S. Senate to pass separate bills to amend and strengthen the ISA. Those separate bills were reconciled by a House/Senate Conference Committee and, on June 24, the resulting bill was passed unanimously by the Senate (99-0) and overwhelmingly by the House (408-8). President Obama signed the bill into law on July 1, 2010.