Russian President Vladimir Putin has reached out to one of the poorest and least predictable states on earth: North Korea. So far, the new Moscow-Pyongyang axis matters little. But the effort demonstrates that Russia can make Washington pay for confronting Moscow over Ukraine.

The United States and the Soviet Union divided the Korean peninsula at the end of World War II. Moscow’s zone became the Democratic People’s Republic of Korea, better known as North Korea, while the U.S. zone became the Republic of Korea, better known as South Korea. But North Korea denounced Moscow in 1991 after it recognized South Korea. Since then, Russo-North Korean relations have been minimal.

In contrast, Seoul provided investment and trade in abundance. After President Vladimir Putin held a summit with South Korean President Park, Russia leaned toward Seoul in denouncing the North’s missile and nuclear programs.

However, Moscow is rebalancing its position. Last year North Korea and Russia exchanged high-level visitors and inked a number of economic agreements. Russia indicated its willingness to host a summit. Both governments talked of “deepening” economic and political ties.

Although Russia’s North Korea initiatives are new, the interests being promoting are old: regional stability, denuclearization, improved transportation links, expanded commercial and energy activities, and enhanced diplomatic clout.

So far Moscow has invested little. There is no aid. Last year the Russian government formally wrote off $11 billion in Soviet-era loans, which were never going to be repaid.

As for security, the Putin government is focused elsewhere. Joint military maneuvers with North Korea are planned for later this year, but no one imagines the two countries will ever fight together. Pyongyang wants to purchase Moscow’s best fighter, the Su-35, but has little money to do so.

Pyongyang desires to diversify its international relationships and find a counterweight to Beijing. The Chinese have grown increasingly irritated with North Korea's determination to build nuclear weapons and refusal to adopt meaningful economic reforms.

Thus, North Korea hopes for Russian investment and trade. The North would welcome another friend on the United Nations Security Council whenever nuclear and human rights issues arise.

For Moscow, North Korea offers some economic possibilities, but the latter’s poverty and unpredictability reduce its attractiveness as a market. Instead, Russia’s chief economic interest in the North is as a transit route—rail, gas, and electricity—to South Korea. In this way the Putin government is interested in north Korea, not North Korea.

As U.S.-Russia relations have deteriorated, especially after events in Ukraine over the last year, Moscow has been looking for other fields to compete with the United States. Pressing for resumption of the Six-Party Talks, intended to peacefully resolve concerns about North Korea's nuclear ambitions, raises Moscow’s diplomatic profile and applies pressure to the United States.

Russia is also applying subtle pressure on Seoul, encouraging it to distance itself from U.S. policy toward Moscow. The Putin government does not expect the South to formally break with America, but would benefit from a less enthusiastic application of U.S.-led sanctions.

Russia also is interfering with Washington’s attempt to isolate and pressure the North. Enhanced economic ties between Moscow and Pyongyang would reduce the effects of existing sanctions and make Moscow less receptive to new U.S. proposals to tighten controls on North Korea.

The Putin government could do more to upend the Korean balance. However, so far the Russo-North Korean performance is largely international Kabuki theater. Greater Russian interest in North Korea will hinder Washington’s efforts to force North Korea to relent. But China was not going to allow that to happen and the Kim regime was not planning to negotiate away its nuclear weapons.

However, as I point out in the National Interest, “Russia’s attention to Pyongyang should remind Washington that Moscow matters to the U.S. Ukraine is of little security interest to America, but Russia may respond to U.S. pressure there by targeting more serious Washington interests elsewhere, such as Iran, Afghanistan, and Korea.”

So far, Moscow has exacted only a small price for U.S. opposition. But the expense could grow. The Obama administration should carefully consider the costs before engaging in a new Cold War with Russia.