President Obama zipped through Afghanistan Tuesday on a previously unannounced visit, signing a key partnership document with Afghan President Hamid Karzai as he prepared to deliver an address to the nation on the anniversary of Usama bin Laden's death. In excerpts released in advance of the address, the president made sweeping statements about the course and eventual conclusion of the Afghanistan and Iraq wars. "We have traveled through more than a decade under the dark cloud of war. Yet here, in the pre-dawn darkness of Afghanistan, we can see the light of a new day on the horizon," he plans...