Just as the House and Senate are set to vote on non-binding resolutions denouncing a troop increase in Iraq, U.S. officials and President Bush ramped up the rhetoric about Iran this week, claiming Iran is supplying weapons to Shiite militias in Iraq.

What’s happening?
Five weeks after the proposal to send 21,500 additional troops to Iraq, a vote expressing disagreement with the President’s decision is expected in the House on Friday and in the Senate on Saturday. Of course these are nonbinding resolutions that merely express disagreement but won’t stop the troops from heading to Iraq or block funding for them.

Meanwhile, U.S. officials and President Bush offered evidence this week that Iran is supplying weapons to Shiite militias in Iraq, though U.S. General Peter Pace seemed doubtful. Officials also reported that Muqtada al-Sadr, leader of the most powerful Shiite militia in Iraq, has fled to Iran. That prompted several lawmakers to comment that the administration cannot move forward with military action against Iran without Congress’ approval.

But how much power does Congress really have?

Congressional powers
Article I of the Constitution establishes the legislative branch, Congress, and gives it the power to declare war, and the purse strings to fund it.

Article II establishes executive power and makes the President the Commander in Chief of U.S. armed forces.

So, the Constitution allows a president to commit troops but not declare war. The War Powers Resolution of 1973 attempts to curtail the president’s power by requiring Congress to approve military action ahead of time or end it after 60 days.

In October 2002, well ahead of the January 2003 strike, Congress approved President Bush’s request to attack Iraq. Now Congress is only symbolically voting against the troop increase, as the troops are arriving, but not halting funding.

The big picture
Remember that the Constitution allows for a checks and balances system—each branch has some power over the other. Congress technically could nix the troop increase but doesn’t want to appear unsupportive of the troops. When it comes to Iran, Bush seemingly has the power to send troops without the support of Congress, but cannot “declare war” or keep them there for more than 60 days.