North Korea has an economy smaller than most American cities. Yet China's president courts it, Russia trades military technology for its soldiers, Japan builds missile defences against it, South Korea organises its national defence around it, and the United States keeps forces within range of its weapons. Washington is again seeking a meeting with Kim Jong Un while its alliance with Seoul frays. That is not an irrelevant country.

What changed is not wealth. It is patronage. In June 2024 Vladimir Putin flew to Pyongyang and signed the Comprehensive Strategic Partnership Treaty, whose fourth article commits each country to come to the other's defence if attacked. North Korea then sent soldiers to fight in Russia's Kursk region — some 11,000 to 12,000 of them, by South Korean and Western intelligence estimates — along with artillery shells and missiles. Fuel, food, cash and, those same services say, military technology moved the other way.

That broke a monopoly Beijing had held for sixty years. North Korea is China's only formal ally: the 1961 Treaty of Friendship, Co-operation and Mutual Assistance remains in force, and it is the only mutual-defence commitment China has made to anyone. For decades the arrangement ran one way, because Pyongyang had nowhere else to go. It has somewhere else to go now. It can take economic support from Beijing and military support from Moscow without belonging to either.

It does not need China and Russia to become enemies. It gains whenever their interests differ enough that neither is willing to let the other hold Pyongyang alone — and that partnership has never settled who is really in charge.

Nuclear weapons secure the rest. The United States, China and South Korea all hold overwhelming conventional advantage, and none can be confident that an attempt to end the regime would stay conventional. Pyongyang has built its retaliatory doctrine so that killing Kim Jong Un would not reliably stop a nuclear response. The point is to make regime change too expensive to attempt.

Geography does the rest of the work. A Korean crisis would force Washington to split ships, aircraft and interceptors between the peninsula and Taiwan, and the ability to open a second front is worth more to Pyongyang than any war it could fight. That leverage grows as American stockpiles thin: the United States has already cancelled strikes for lack of munitions.

None of this is free. North Korean soldiers have died in numbers in Kursk — thousands of casualties, by Seoul's estimate — and every shipment deepens a dependence on Moscow that may outlast the war. Roughly nine-tenths of North Korean trade still runs through China.

But that dependence cuts both ways. Beijing wants a buffer state: not a collapse, not a refugee flood, and not American troops closer to its border. Squeezing Kim hard enough to matter risks producing exactly those things, which is why Xi Jinping went to Pyongyang himself.

North Korea cannot dominate Northeast Asia, and it does not need to. A country that can change the calculations of China, Russia, Japan, South Korea and the United States is not a minor player. It is poor, isolated and dangerous — and it is the pivot on which the region now turns.