The NYT warns today that Barack Obama, if he wins the Democratic nomination, will be subject to a withering Republican attack based on much sharper policy contrasts between him and McCain than those that exist between Obama and Clinton.

Such media coverage is creating a fascinating story line in the run-up to the critical March 4th primaries in Texas, Ohio, Vermont and Rhode Island. Are we seeing a preview of an Obama-McCain campaign to come?

If so, expect foreign and security policy to occupy a major part of a no-holds-barred debate. Consider, for example, the rhetoric McCain and Obama employed today at separate appearances in staunchly pro-military Texas. McCain cited (as he often does) the "transcendental challenge of the 21st Century, which is Islamic extremism," and his commitment to track Osama bin Laden "to the gates of Hell" in order to "bring him to justice."

Obama's comments, in front of a veterans' group, gave greater emphasis to fulfilling the country's commitment to caring for returning veterans, as well as his own standard rhetoric about being "right" on Iraq — unlike Clinton, McCain and Bush.
However, McCain took an additional line of attack in his remarks today. Not only focusing on the dangers of a hasty withdrawal from Iraq, McCain jumped to Obama's critique of NAFTA as implicitly undercutting the Canadian consensus needed to continue Canada's military engagement in Afghanistan.

This is a more nimble and nuanced reference to the links between different foreign policy issues than we have seen so far in the primary season. It may presage a more serious and (hopefully) substantive foreign policy debate over the summer.

There is a tactical danger for Obama in looking beyond the March 4th primaries. (Hillary is still ahead in Ohio, according to all the polls.) But he has no choice. Obama is now being forced to carry on two simultaneous campaigns — against McCain as well as Clinton. If he appears weak or ineffective in responding to a feisty war hero on security issues, he will give Hillary a boost going into next Tuesday.