Putin and Kim Jong Un are getting alarmingly close, and it’s put US ally South Korea in a predicament

The Russian president “is casting his lot with North Korea,” Sue Mi Terry, a senior fellow for Korea studies with the Council on Foreign Relations, told Business Insider.

The play signals that “he has abandoned hopes of having some sort of relationship with the West,” she explained, adding that “there is a sense that what’s happening between Russia and North Korea is not a short-term tactical move.”

The pact’s reverberations were felt almost immediately, particularly by North Korea’s neighbor to the south. Just hours after North Korean state media revealed the details of the agreement, a South Korean senior presidential official suggested it would consider sending lethal aid to Ukraine directly, a notable shift from its current policy of providing weapons via the US.

The remarks were met with a quick threat from Russia, which appeared undeterred.

“Those who supply these weapons believe that they are not at war with us,” Putin said, adding that Russia reserves “the right to supply weapons to other regions,” including North Korea.

His remarks essentially tell Seoul that if it goes all-in on direct support for Ukraine, Moscow can very easily make North Korea into an even more formidable adversary.

While South Korea’s long been sending weapons via the US to Kyiv, there are questions about how much more aid it could provide should it change its stance. Seoul’s current annual production rate is only about 200,000 155mm artillery shells, and it likely doesn’t want to dip into its own stockpiles and risk shortages should it face a fight with North Korea.

The South does, however, have a significant stockpile of 105mm shells that could be beneficial to the Ukrainians. The 105s have less reach and power, but South Korea has millions of them — and they may be expiring soon, the Center for Strategic and International Studies think tank explained earlier this year.

Ultimately, perhaps South Korea’s greatest concern is the conflict in Ukraine spilling over onto the Korean peninsula. With Putin supporting North Korea, tensions are higher between Pyongyang and Seoul, and the two could find themselves on the brink.

That’s not a desirable outcome. The US obviously doesn’t want to see its foes teaming up, but even China may find itself almost paralyzed on how to respond to a new Russia-North Korea pact, as it historically likes to keep a strong influence over North Korea and doesn’t like to see Putin and Kim grow closer. “This relationship is as bad for China as it is for the United States,” Cha said.