A month after Russia informed the U.S. that it is suspending participation in the last remaining nuclear pact between the two countries, a senior Pentagon official said on Tuesday that Moscow is now refusing to hand over data on its nuclear warheads, due at the end of this week. In response, the U.S. will not provide Russia with data on its deployed strategic warheads, Assistant Secretary of Defense for Space Policy John Plumb said on Capitol Hill. Plumb told a hearing of the House Armed Services subcommittee on Strategic Forces that the U.S. had pressed the Russians on the issue...