In the U.S., spending is controlled by Congress, not by the President. Congress sets the budgets and authorize funds. The spending by Congress is approved or disapproved by the President, unless congressional override is made achieved with a 2/3 vote in Congress (then the President is unable to have any effect on the spending). The President can suggest what to spend government dollars on, but cannot actually introduce a bill Congress can vote on to authorize spending --- only a member of Congress can do that. Funds for the Iraq War were approved by Congress, along with corporate bailouts and special interest funding. Without them introducing spending bills and approving them, all U.S. programs would halt.
For the last four years, and in most of the last 40 years, the Congress has been controlled by Democrats, and they seem to spend U.S. money with no responsibility at all. That's really why the U.S. is in a huge mess with government spending.
Bush II, Clinton, Bush I and even Reagan have had little effect in controlling the wild spending in Congress, and they have all tried to do so.
The U.S. voter needs to boot out the scoundrels that control Congress, and that is pretty much Democrats. It's hard to do, though, since these congress people help to fund projects in the voter's neighborhood.
Generally, Republican congressional people are much better in reducing U.S. government spending than their Democrat counterpart, but the free-spending Democrats manage to get re-elected over and over.