Sen. John McCain, Ranking Member of the Senate Armed Services Committee, will have the opportunity to ask questions of Gen. David Petraeus and Ambassador Ryan Crocker today on Capitol Hill. The hearing is set to begin at 9:30 AM EDT. McCain will be the second to ask questions, so his turn should come during the morning hours. It should be a very eventful day in Washington!

It is doubtful that Gen. David Petraeus or Ambassador Ryan Crocker will say anything that is remotely unexpected when they appear later today before two Senate panels to update Congress on the conditions on the ground in Iraq more than 14 months after President Bush announced his plan to send nearly 30,000 additional U.S. troops to fight the war.

Petraeus and Crocker are anticipated to tell lawmakers that significant progress has been made in improving the security situation, and that the U.S. and Iraqi forces have dealt a critical blow to Al Qaeda in Iraq.

Petraeus will likely testify that he plans to recommend to the president a temporary pause in troop withdrawals in July after the last of five U.S. combat brigades are sent home without replacements. And Crocker will acknowledge that Iraqis have failed to take advantage of the breathing space created by the improved security situation, while point to signs that significant gains are within reach for the Iraqis.

In fact, as the war in Iraq appears on center-stage once again, it seems as if Petraeus and Crocker—the two Americans who are arguably closest to situation in Iraq—will be playing supporting roles in the latest political drama to unfold on Capitol Hill.

For the first time in months, the three remaining major presidential candidates will take a break from the campaign trail and return to Washington to hear Petraeus and Crocker testify.

The political stakes are enormous, as the presumptive Republican nominee Sen. John McCain and the Democratic contenders, Sens. Hillary Clinton and Barack Obama, will offer starkly different views in what is a golden opportunity to show voters how they may operate as commander-in-chief.

McCain and Clinton sit on the Armed Services Committee, which meets this morning with Petraeus and Crocker. Obama, sits on the Foreign Relations panel, which will meet with the commander and diplomat later in the afternoon. As one of the most junior members on the committee, Obama won't have an opportunity to pose a question on Petraeus and Crocker until late in the day.

As the ranking Republican member on the panel, McCain will be second to speak. He will almost certainly express concern that drawing down forces to quickly could put the hard-fought gains at risk.

Clinton and Obama as well as other Democratic leaders will make the argument that, at best, U.S. forces are treading water in Iraq. They've both argued that the U.S. presence in Iraq is putting an enormous strain on U.S. troops and an overwhelming financial burden on an American economy that is in a tailspin.

Both Democrats have pledged to begin a withdrawal of troops soon after they take office if they were to win.

Yesterday, McCain fired one of his fiercest salvos on his opponents to date for making promises to withdraw from Iraq.

"Our goal is an Iraq that no longer needs American troops," McCain said during a campaign stop in Kansas City. "And I believe we can achieve that goal, perhaps sooner than many imagine. But I do not believe that anyone should make promises as a candidate for president that they cannot keep if elected. To promise a withdrawal of our forces from Iraq, regardless of the calamitous consequences to the Iraqi people, our most vital interests and the future of the Middle East is the height of irresponsibility. It is a failure of leadership."