55 sailors in the process, and an American helicopter was shot down, killing the two pilots. A number of researchers and former military personnel contend that the United States carried out Black operations against Iranian military targets during the war. Lt. Col. Roger Charles, who worked in the Office of the Secretary of Defense at the Pentagon, says the Navy used specially equipped Mark III patrol boats during the night, with the intent of luring Iranian gunboats away from territorial waters, where they could be fired upon and destroyed. "They took off at night and rigged up false running lights so that from a distance it would appear there was a merchant ship, which the Iranians would want to inspect." Information collected from Operation Eager Glacier, a top-secret intelligence-gathering program, was also used to bomb manufacturing plants inside Iran by the CIA. The USS Stark incident An Iraqi jet fighter mistakenly attacked the USS Stark in May 1987, killing 37 servicemen and injuring 21. But attention in Washington was on isolating Iran; accepting Saddam's apology for the error, the White House criticized Iran's mining of international waters, and in October 1987, the U.S. attacked Iranian oil platforms in retaliation for an Iranian attack on the U.S.-flagged Kuwaiti tanker Sea Isle City. Longer term interests In response to further Iraqi chemical attacks on Kurdish civilians after the August 1988 ceasefire with Iran, U.S. senators Claiborne Pell and Jesse Helms called for comprehensive economic sanctions against Iraq, including an oil embargo and severe limitations on the export of dual-use technology. Although the ensuing legislation passed in the U.S. Senate, it faced strong opposition within the House of Representatives and did not become law. In a rare rebuke, Secretary of State George Shultz condemned Iraq's "unjustified and abhorrent" attacks, which Shultz's assistant Charles E. Redman characterized as "unacceptable to the civilized world." Even after these pronouncements, however, the State Department advised against sanctions. In October 1989, President Bush signed NSD 26, which begins, "Access to Persian Gulf oil and the security of key friendly states in the area are vital to U.S. national security." With respect to Iraq, the directive stated, "Normal relations between the United States and Iraq would serve our longer term interests and promote stability in both the Persian Gulf and the Middle East." See also CIA activities in Iraq International aid to combatants in the Iran–Iraq War Iran Air