Here's why Alexander Lukin, director of the Center for East Asian and SCO Studies at the Foreign Ministry's Moscow State Institute of International Relations, or MGIMO, thinks Russia should favor controlling North Korea's nuclear weapons:

Currently only a few countries have nuclear weapons, and Russia and the United States have many times more than any of the other nuclear states. If the current structure of the United Nations guarantees Russia special status among other countries as one of the five permanent members of the Security Council, then the nuclear-weapons non-proliferation regime is at the base of Russia's position as one of the world's two most powerful countries. This means the nuclear weapons proliferation seriously devalues Russia's influence in the world. It is all very simple: the more nuclear states there are, the less Russia's comparative military might become. This is a purely pragmatic consideration, to which can be added a number of other negative consequences from further nuclear proliferation: an increased probability of nuclear conflict, threats to national security in the Far East, and so on.

So Lukin couldn't care less about world peace, but he feels that if North Korea has nukes it will undermine Russia's ability to ply the world with nuclear blackmail of its own, apparently the sole potential basis of Russian military power.

And he's rather mercenary about it. He thinks that not only can Russia help the US to block North Korean nukes, but it can extract favors from the U.S., including selling Georgia down the river, in return for doing what is in Russia's interest anyway. He writes:

There is also the possibility for horse-trading here. For example, Russia stiffens its position on Korea -- which is good for Moscow anyway -- in exchange for a softer U.S. position on Georgia (an operation the Foreign Ministry seems to have carried out successfully). Active defense of Russian interests is not compatible with the primitive anti-Americanism characteristic of pseudo-patriots and some highly placed figures apparently unable to overcome their Soviet special-services training. While possibly taking a more assertive position on some questions, it is essential to work closely with Washington and the West as a whole on others. Genuine patriotism is not made of hysterical anti-Westernism, but of strengthening one's own country. To paraphrase the words of Petr Stolypin, prime minster under Nicholas II, we can say, "They need a weak America, we need a strong Russia." Taking this literally, the Kremlin leadership still occasionally lets itself be influenced by traditional feelings that ultimately boomerang and produce a foreign policy that is ultimately unproductive for Russia.

Further, he claims that Russia should favor the unification of South and North Korea as a way of expanding Russian influence in the region:

The creation of a united Korea would be good for Russia, both geopolitically and economically. First, a united Korean state -- which would undoubtedly be based on the far more viable South Korea -- will be less dependant on U.S. influence, since its influence on Seoul is largely dependent on the threat from the North. Second, a united Korea's relations with Japan will be tricky due to the historical problems between the countries. It would also look with some trepidation at its huge and booming neighbor, China. For Russia, which also has serious and stubborn difficulties with Japan, and for which a powerful China represents a strategic challenge, a united Korea could become a geopolitical partner in the same mold as, for example, India. In addition, an economically advanced and unified Korea that is still closer to Russia's level of development than that of more advanced Japan could make a significant contribution to the development of the Far East and Siberian regions. The population of these regions traditionally favors collaboration with the Koreans and has fewer reservations about them than it does, for example, about the Chinese.

He castigates classic Soviet men for not being as enlightened as Neo-Soviet men like himself. He states: "When I hear 'patriots' like General Leonid Ivashov, former head of the Defense Ministry's department for international cooperation, saying nuclear weapons are the only defense some countries have against possible aggression by the United States, and that Russia should support these countries in this, I feel like accusing them of treason." In other words, sure we want to destroy the Americans, and take over the world and obliterate democracy, but there's a right way and a wrong way to do it. La Russophobe's guess is that he's channelling Vladimir Putin.