WASHINGTON (AP) — If Republicans win the Senate, the Pentagon should brace for constant grilling from Sen. John McCain, who has found fault with nearly every aspect of President Barack Obama's national security policies. The senator who lost to Obama in the 2008 presidential election has never suffered fools — or equivocating witnesses — gladly, and he would be certain to use his new perch for tough questioning about Iraq, Syria, Iran, Afghanistan and military spending. The Arizona lawmaker has made it clear that if Republicans win the Senate, he would pursue the chairmanship under GOP rules that allow a senator to serve as chairman for six years despite hitting the six-year limit as ranking member. Mississippi Sen.