WASHINGTON (AP) - President Bush signed a bill Friday to pay for military operations in Iraq after a bitter struggle with Democrats in Congress who sought unsuccessfully to tie the money to U.S. troop withdrawals. Bush signed the bill into law at the Camp David presidential retreat in Maryland, where he is spending part of the Memorial Day weekend. In announcing the signing, White House spokesman Tony Fratto noted that it came 109 days after Bush sent his emergency spending request to Congress.``Rather than mandate arbitrary timetables for troop withdrawals or micromanage our military commanders, this legislation enables our servicemen and women to follow the judgment of commanders on the ground,'' Bush said in a statement. ``This important bill also provides a clear roadmap to help the Iraqis secure their country and strengthen their young democracy,'' he said. ``Iraqis need to demonstrate measurable progress on a series of benchmarks for improved security, political reconciliation and governance. These tasks will be difficult for this young democracy, but we are confident they will continue to make progress on the goals they have set for themselves.''