Ten months after being sworn in, Joe Biden finally met with Xi Jinping. The summit is online, not face-to-face. But after the tension between Washington and Beijing lasted for months, the fact that the leaders of the United States and China had a three-hour conversation was very important.

An obvious breakthrough at the summit was that the United States announced an agreement, and China and the United States held talks on their nuclear arsenals. Just a few days ago, at the United Nations Climate Summit in Glasgow, the two countries announced a joint plan to tackle climate change.

The outbreak of dialogue diplomacy this time is a sign that Sino-US relations have tended to stabilize and may even improve. Popular talk about the new cold war between the two countries may now give way to talk about a new detente.

It makes sense to be cautious. The exact form and timing of the nuclear negotiations have not yet been determined. Of course, there is no sign that Beijing intends to reduce its huge investment in nuclear weapons; or that the United States plans to reduce the modernization of its own larger nuclear arsenal.

The US-China joint climate statement is also weak in details and commitments—especially when compared with Xi Obama’s 2014 statement, which paved the way for the Paris climate agreement the following year.

The summary released by both sides of the Xi Biden talks also emphasized the possibility of the continuing conflict in Taiwan. Xi Jinping’s language is confrontational. He warned that politicians who encouraged the island to fight for independence were “playing with fire” and would “self-immolate.”

Although this is standard official speech in China, it is still shocking to hear that the Chinese leader publicly hints at war with the United States. Biden also acknowledged this possibility, saying that the two leaders have a responsibility to ensure that the competition does not “get into conflict.”

The severity of these warnings reflects the real danger of the situation. Both Washington and Beijing accused each other of escalating tensions. China is sending more and more fighters to Taiwan’s air defense identification zone. Biden recently stated that the United States would protect Taiwan from any attacks by China, which broke the traditional American policy of “strategic ambiguity”, although this was quickly clarified. The United States has also tried to expand diplomatic space with Taiwan, which has also angered Beijing.

The talks between Biden and Xi did not seem to have played any role in easing tensions on the island. The summary issued by both parties only confirmed their current position and mutual suspicion.

There are also few signs of progress in trade. The tariffs and other punitive measures imposed by the Trump administration on China have not yet been cancelled, and negotiations have not indicated that this situation will change soon.

But if the US-China negotiations on nuclear and climate issues gain momentum, the more positive tone of bilateral relations may also permeate economic issues. The change in tone is of course welcome. Some recent meetings between senior officials of the two countries have fallen into public quarrels.

The competition between China and the United States remains widespread and dangerous. Biden’s meeting with Xi did not change this underlying reality. But the two leaders have begun a dialogue, and they can now build on this. This week’s summit should be the first of many summits.