'No limits': Russia, China and US enter new nuclear arms race

Some of the drivers that are relevant here, in terms of thinking about how big of an arsenal the U.S. might actually want, have to do with the deterrence of attacks against the United States themselves, against US territory, but also the ability of the US to extend deterrence to its allies in Europe and elsewhere, and to be able to do that. The US needs to, for instance, make credible the fact that it could carry out effective damage limitation strikes against Russia's nuclear capabilities, and that it has a survivable second strike capability following any Russian retaliation. So there are a couple of different drivers, again, that go into calculating the numbers that the United States might want on the part of the Russians in similar considerations, although they don't have the same extended deterrence commitments that the United States has. But in Russia, strategic culture also plays an important role, as it does in other states, but in the case of Russia and the Soviet Union before it, they very much see themselves as a leading world power and a leading power that needs to have parity with the United States when it comes to its nuclear arsenal. So that's also been an important driver of the high numbers of systems for Russia."