Iran Sanctions Enhancement Act of 2007 - Amends the Iran Sanctions Act of 1996 to direct the President to impose two or more sanctions under such Act if a person has, with actual knowledge: (1) made an investment of $20 million or more (or any combination of investments of at least $5 million which in the aggregate equals or exceeds $20 million in any 12-month period) that directly and significantly contributed to Iran's ability to develop its petroleum resources; or (2) on or after December 31, 2007, provided Iran with refined petroleum resources or engaged in an activity that could contribute to the enhancement of Iran's ability to import refined petroleum resources. (Under current law, imposes sanctions upon investments of $40 million and does not include refined petroleum resource imports.)
Extends existing presidential waiver authority to such activities.
Directs the President to report to the appropriate congressional committees every six months on such activities.