Back then the United States was looking for a way to back Saddam Hussein in his war against Iran—without quite saying so. He was a thug, but the Iranians had humiliated the Reagan administration by training the Hizbullah shock troops that forced the United States out of Lebanon in 1984 and by revealing the scandalous arms-for-hostages deals the Reagan administration cut in 1986. So by 1987 the CIA (with Gates effectively running the show) started sharing satellite intelligence with Saddam that allowed him to fight more effectively against Iran.

By coincidence according to Wise's history, by conspiracy according to the Iranians, the big naval battle the United States launched against Iran's little fleet in April 1988 happened at exactly the same time that Saddam launched a massive offensive to retake the strategic Faw Peninsula. Thanks to his American-supplied intelligence and his huge arsenal of chemical weapons, he succeeded. Months later, after eight years of war, Iran admitted defeat.

Today Saddam is no longer a problem. But Iraq is a huge one. The government the Americans helped install there is very close to the Iranians. So are the militias now killing American soldiers in Iraq almost every day. A safe bet about this dangerous situation is that any major confrontation with Iran on land or at sea will make life even more hellish for U.S. forces in Iraq.

Today Iran is on its way to becoming a nuclear power. Whether it builds weapons, as the United States claims it will do, or keeps its technology purely peaceful, as it insists it intends, its nuclear knowledge changes all strategic calculations in the region.

But today the most volatile danger zone remains at sea, because today the U.S. Navy and American ships face threats that overlap with those Iran might pose. Twenty years ago there was no Al Qaeda. Now there is. And while its most devastating attacks have been from the air, it also developed techniques for blowing up ships at sea. In October 2000 Al Qaeda hit the USS Cole in the Yemeni harbor of Aden, killing 17 sailors; in October 2002 it hit the French oil tanker Limburg, killing one crew member, injuring a dozen more and doing tens of millions of dollars worth of damage. That the mastermind of those two attacks, Abd al-Rahim al-Nashiri, was caught in late 2002 and is now in U.S. custody at Guantánamo is cause for some relief, but hardly complacency.

To protect against these threats, what are called "embarked security teams" of about a dozen U.S. military personnel are now put on American-flag merchant ships working with the 5th Fleet from the Suez Canal to Pakistan and from Kuwait to the southern border of Kenya. But there are tens of thousands of little boats in those waters. Are they Al Qaeda? Are they Iranian Revoluionary Guards? Or just fishermen and merchants? To warn them away the American security teams try radio contact, loudspeakers, a flare, then .50 caliber rounds fired into the water in front of the boats or beside them. In March one of those bullets hit an Egyptian peasant on the Suez Canal and killed him.