“If Iran continues with its program for developing nuclear weapons, we will attack it,” said Deputy Prime Minister Shaul Mofaz in today’s Yedioth Ahronoth, the Israeli newspaper.  “The sanctions are ineffective.”

Many assume that no Israeli government will let the Iranians build a nuclear arsenal, and Mofaz’s words — he also used “unavoidable” in the same sentence as “attacking Iran”– constitute the most explicit threat to use force to date.  Because it looks unlikely that the Iranians will stop their program to enrich uranium, war in the Persian Gulf is becoming inevitable.

So this appears to be the last chance for the Bush administration to take the lead in stopping Iran.  And it is perhaps the last chance for us to maintain the current international system.  After all, Mofaz’s comments highlight Washington’s failure to maintain stability.  Countries are starting to take matters into their own hands, and this signals that the world could transition from the American-led global order to another type of international system.  In that new system — the Chinese use the term “multipolar”– many countries will be able to bring about drastic change.  When there are a significant number of actors, great powers will no longer be able to maintain global order.  Events in a multipolar world, therefore, have the potential to flare and lead to wholly unpredictable consequences.

Like a war between Iran and Israel, for instance.  Of course, many analysts will not take Mofaz’s words seriously.  They will say he does not speak for Ehud Olmert and, in any event, the prime minister will be departing soon.  Perhaps all this is true, but the fact that he spoke is a sign that we could soon embark on an era of fundamental, fast, and uncontrollable change.  When that era begins, all our assumptions about international politics will become obsolete.

The next war in the Middle East, in short, might change everything.  So the stakes for the United States could not be higher.  Now is the time for President Bush to act.