Despite that humiliation, some in Tehran came away believing that a combination of mines, missiles and the fervor of the Revolutionary Guard members manning small boats could compete with the might of the United States Navy in the confined waters of the Persian Gulf. So, off and on for 20 years, the Iranians have been initiating small incidents, testing the limits of what America will accept.

While the events earlier this month were ambiguous, there can be little doubt that the Iranian actions were part of this continuing pattern. Even if one believes Tehran’s explanation that the interaction was routine and harmless, the fact is that Iranian small ships came within 500 yards of American warships. At this range, our sailors would be well within the effective range of rocket-propelled grenades and machine guns, thus neutralizing the range advantage of our more advanced weapons.

This is why President Bush was correct in calling Iran’s actions “provocative” and having the State Department place Tehran on official notice that there will be serious consequences should the small boats continue their actions.

To forestall another confrontation or prevent an escalation, which would not be in our interests, the United States needs to do more. Washington should begin by marshaling the support of its allies that already have ships in the gulf and might find themselves in an equally dangerous confrontation. After the 9/11 attacks, several European navies (as well as Australia’s and Canada’s) sent large forces to augment the United States effort in safeguarding the sea lanes of the Middle East from terrorism. The Bush administration should harness this coalition by asking them to let Tehran know through their own diplomatic channels that any attempt by the Revolutionary Guards to interfere with the free navigation of international waters will be treated no differently from a terrorist attack.

Iran’s motivations are not entirely clear. It may be that this systematic harassment is an attempt to ascertain the American rules of engagement. It may also reflect increased Iranian hubris. Or it may be an initiative of local commanders acting without permission from the Tehran government, which would appear to have little to gain by blatantly threatening the United States. While the Revolutionary Guard’s orders originate from the central government, its commanders are given considerable autonomy. Still, whatever the motivations, the United States and its allies must make clear that it is Tehran’s responsibility to control all its forces and that it will be held accountable for their actions.

If Iran is determined to have a clash at sea, our military response should be forceful and precise, one that would remove the threat to the sea lanes while reducing the chance of escalation and minimizing the chances of a wider war. History  the events of 1988  suggests that such a measured use of force is not only possible but can be effective.