A revealing account of the US conflict with Iran over the Persian Gulf during the Reagan era—and the groundwork it set for today's tensions.   In May 1987, the US frigate Stark was blown apart by an Iraqi jet fighter in the Persian Gulf, jumpstarting a major conflict with Iran that came to be known as the Tanker War. In America's First Clash with Iran, author Lee Allen Zatarain employs Pentagon documents and firsthand interviews to reveal the full story of a conflict that may have presaged further battles to come.   At the climax of the Iran-Iraq War, Iran was losing on the battlefield. Ayatollah Khomeini decided to close the Persian Gulf against shipping from Iraq's oil-rich backer, the emirate of Kuwait. When the United States sent a fleet to the Gulf, raising the Stars and Stripes over Kuwait's commercial tankers, a tinderbox was set off.   The Iranians laid mines throughout the narrow passage and launched attack boats against both tankers and US warships. The US Navy fought its largest surface battle since World War II against the Ayatollah's assault boats. As Saddam Hussein looked on, Iranian gunners fired missiles against US forces—actions which, if made known at the time, would have required the US Congress to declare war against Iran.