WASHINGTON D.C. — Tens of thousands of sailors and Marines are currently involved in the biggest U.S. naval exercise in a generation, spanning 17 different time zones, as they prepare for possible future conflict with China or Russia, according to The Defense Post. <br /> <br /> <br />Aircraft carriers, submarines, planes, unmanned vessels and around 25,000 personnel will take part in what is known as Large Scale Exercise 2021, according to Military.com. <br /> <br /> <br />Vice Admiral Gene Black, commander of the U.S. Sixth Fleet, said in a Navy press release that the exercise will “test our commanders across the spectrum of naval warfare from the tactical to the strategic, integrating the Marine Corps to demonstrate the world-wide fleet’s ability to conduct coordinated operations.” <br /> <br /> <br />Three dozen units will participate in the physical aspects of the large-scale exercise, but more than 50 units will join the exercise remotely, according to Lieutenant Commander Tabitha Klingensmith of U.S. Fleet Forces Command, cited by Military.com. <br /> <br /> <br /> <br />