WASHINGTON (AP) — War-weary Americans will support more fighting in Afghanistan once they understand the perils of losing, President Obama declared Tuesday, announcing he was ready to spell out war plans virtually sure to include tens of thousands more U.S. troops.Eight years after the Sept. 11 attacks led the U.S. into Afghanistan, Obama said it is still in America’s vital national interest to “dismantle and destroy” al-Qaida terrorists and extremist allies. “I intend to finish the job,” he said.