If the Senate Democrats passed a bill approving funds for the troops, and attached an amendment saying Bush also had to set off a nuclear bomb over New York City if the bill passed, would it be Bush who is "defunding the troops" when he vetoes it?
Your comparison is absurd as the Senate and House who represents a cross section of the American people would never attach an amendment to set off a nuclear bomb over New York City and it would almost be impossible for them to do so as they would have to get 269 people who represents such a broad base of Americans to agree with it. On the other hand Bush being one man is likely to be insane enough to do so and would be able to because there isn't anyone to check him like in Congress where you need to obtain a majority of the vote for something to pass. While it is very unlikely that 269 men and women would decide to nuke New York City it is far more likely that one man would decide to do so. It is this comparison that 269 members of Congress would desire to nuke New York City while the President as a benign leader would never think of doing any such thing and that is truly absurd. While Congress does not have the authority of conducting the every day activity of the military they do have the constitutional authority to set U.S. policy even in terms of the military.
These words, "all legislative powers herein granted shall be vested in a Congress of the United States, which shall consist of a Senate and House of Representatives" seem to mean nothing to Bush. He doesn't seem to care that it is Congress who shall, "have power to lay and collect taxes, duties, imposts and excises, to pay the debts and provide for the common defense and general welfare of the United States." He also fails to understand that Congress shall, "make rules for the government and regulation of the land and naval forces." Anyone who understands how the terms government and regulation were used at the time of the drafting of the Constitution would be aware that regulation was referring to the deployment of troops as opposed to the government of the troops.
This power to regulate the troops was seen as the power to declare war and to define how that war would be fought as the distinction was being made between the role of a King and a President. The former having the power to determine how to fight the war and the latter having the power to direct those forces as directed by Congress. The President as Commander in Chief would essentially be "the General in Chief or Admiral in Chief" of the Army and Navy and of the militia when Congress has called them into the actual service of the United States but he would not set policy.
The only real question here is, will the Dems find enough Useful Idiots among their constitutents to believe it wasn't their own act that defunded the troops, or not.
The Congress sets U.S. policy because this is a republic and not a monarchy. Congress has passed funding for the military and continues to do so. If the President vetoes the action of Congress because it puts conditions on the use of those funds than it is he is refusing to fund the war and he will have to wait for Congress to again pass legislation in this regard but I doubt very much that Congress is simply going to acquiesce to allowing Mr. Bush to set U.S. policy.
The President does not originate legislation but either vetoes acts of Congress or he accepts them as is. The Congress won't be refusing to fund the Iraq war instead it will be the President who does so by vetoing Congress in its fulfillment of its constitutional responsibility to determine funding and to set U.S. policy. Congress isn't defying the President in the fulfillment of his constitutional duties instead it would be the President who is defying Congress in the fulfillment of its constitutional responsibilities.
It is obvious that the President does not set policy as Commander in Chief and it wasn't until recently that the Presidency has sought to obtain this power to themselves. Regardless of what happens it will always come back to Congress to determine funding and to set U.S. policy. If the President vetoes the act of Congress than he will still have to wait for them to perform their duty by passing another act yet at the end of the day it will be he who is abusing the power of the veto by attempting to prevent Congress from fulfilling its responsibilities.