Beyond Iraq's borders, the options become difficult: engaging in hot pursuit against weapon supply lines over the Iranian border, or striking explosive factories and staging areas within Iran. This sort of escalation is opposed both by the Iraqi government and by American military leaders. The Department of Defense fears what is called "escalation dominance" -- meaning that in a broadened conflict, the Iranians could complicate our lives in Iraq and the region more than we complicate theirs.
Syria, however, is what one former administration official calls "lower hanging fruit." The provocations are nearly as severe. Syria's Baathist regime provides a base of operations for their Iraqi Baathist comrades involved in the Sunni insurgency. Suicide bombers from Saudi Arabia and North Africa arrive by plane in Damascus, and, with the help of facilitators, some 50 to 80 cross the border into Iraq each month. The Syrians say they lack the ability to stop them; what they lack is the intention.
Pressuring Syria is not without its own complications. The regime can cause more suffering for its hostage Lebanon, or increase tensions with Israel. And our European allies are weaker on sanctions against Syria than against Iran, because Syria is not a nuclear threat.
But here the forceful options are more serious. Recent successful operations in Anbar province were undertaken, in part, to disrupt the trail of suicide bombers that leads through Syria. It might also make sense to pursue targets into Syria on this theory: The Syrians say they are powerless to stop the flow of murderers killing innocent Iraqis, so we will try.
Increasing pressure of all types on Syria would demonstrate that being part of an anti-American alliance with Iran brings unpleasant consequences. And when that pressure builds sufficiently, it becomes possible to offer Syria a way out that separates it from Iran.
These are realistic responses to the serious provocations of Iran and Syria: Ramping up economic pressure on both regimes; intensifying operations within Iraq against foreign influence; and taking limited but forceful actions against Syria's Ho Chi Minh Trail of terrorists.
In combination with the Petraeus strategy, these measures hold out the promise of something unthinkable a few months ago: America, once again, on the strategic offensive.
Michael Gerson
Michael Gerson writes a twice-weekly column for The Post on issues that include politics, global health, development, religion and foreign policy. Michael Gerson is the author of the book "
Heroic Conservatism" and a contributor to Newsweek magazine.
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