U.S. carrier navigates crowded waters as North Korea tensions mount

By Greg TorodeABOARD THE USS RONALD REAGAN, South China Sea (Reuters) - As the commanders of the largest U.S. warship in Asia seek to maintain operational readiness amid protracted tensions over North Korea, they find themselves keeping one eye on China, too.On Saturday, as F-18 Super Hornet jet fighters roared from the decks of the USS Ronald Reagan aircraft carrier during routine drills deep in the South China Sea, two Chinese frigates maintained a constant line-of-sight vigil.Other times, Chi