Over the years, both sides have cut their nuclear arsenals on their own initiative. The United States now has about 850 strategic delivery vehicles (very close to the new treaty's limit), and Russia has about 600 (below that limit). The U.S. has 2,252 bombs and warheads, while Russia has about 2,787—closer to, or a little above, the '91 treaty's limits. So the new treaty will force some cuts on both sides—but not as deeply as these numbers suggest.