DAKAR, Senegal (AP) - U.S. Navy sailors may board thousands of commercial ships in international waters to search for weapons of mass destruction under a landmark pact between the United States and Liberia, the world's No. 2 shipping registry. State Department spokesman Richard Boucher confirmed Friday that the United States is seeking similar deals with other nations, but he declined to identify them. Wednesday's accord - the first of its kind, Boucher said - comes amid fears that terror networks would use ships for attacks, taking advantage of comparatively lax security on the waters after crackdowns in the skies....