“Under the current situation, all relevant parties need to remain calm and restrained and jointly seek de-escalation and lower strategic risks through dialogue and consultation,” said Chinese foreign ministry spokesperson Lin Jian on Nov 20. China’s comments came a day after Vladimir Putin approved a decree lowering the threshold for nuclear strikes.  At first glance, it looks as if Beijing is worried that the war in Ukraine will escalate. It’s sometimes hard to know for sure what the Chinese leadership actually thinks but leader Xi Jinping is almost surely comfortable with Vladimir Putin’s threats to use his most destructive weapons against Ukraine.  Why? There are two principal reasons.   First, events over the past couple of years suggest that Beijing is fully behind Putin’s war effort.  As an initial matter, China greenlighted the invasion, evident from its joint statement with Russia declaring the “no limits” partnership, issued on Feb. 4, 2022, while the Russian leader was visiting the Chinese capital.  The statement was released just 20 days before the Russian attack. The attack might have been earlier but Putin evidently acceded to Chinese wishes and waited until the end of the Beijing Winter Olympics to hit the former Soviet republic.  From the very beginning of the war, Xi Jinping’s regime has kept Putin in the fight by providing Russia with diplomatic, propaganda, banking, economic and lethal assistance.  Moreover, China has been providing military personnel as “technical advisers” on the ground for about a year. “These advisers were charged with maintaining the Chinese-provided drones that Wagner mercenaries were deploying,” military analyst Brandon Weichert told me. “There are numerous reports of the advisers deploying into combat with those mercenaries.”   Putin is bold. I think Xi sees Putin as an essential partner because he is willing to do what Xi would like to do himself: disrupt the international system.  Xi has adopted a page out of Mao Zedong’s “peasant movement” playbook of promoting “chaos” to achieve worldwide Chinese rule, and Putin is Xi’s chaos maker. What better way to cause chaos than to threaten nuclear war?  China and Russia have effectively formed an alliance because Xi and Putin see the world in the same terms, they articulate interests in the same way, and they have identified the same enemy: the United States.   China’s and Russia’s ultimate ambitions are different — Putin seeks to reassemble the Russian empire to its greatest extent and Xi wants to rule the world and the near parts of the solar system — but their conflicting goals do not prevent them in the here and now from coordinating policies. Their militaries continually practice for war together, on land and at sea.  Putin is so important to China that the Chinese leader, I think, believes Russia must prevail in Ukraine and use every weapon at its disposal if that is what it takes.  Second, the Chinese regime has for decades been making Putin-like threats of its own. Beijing has pledged to not use nuclear weapons first, but it has throughout this century made threats to do exactly that.  For instance, in July and September 2021, China threatened to nuke Japan for supporting Taiwan and Australia for joining AUKUS, the submarine-building coalition of Australia, the United Kingdom and the U.S. In March 2022, the Chinese Ministry of Defense promised the “worst consequences” for countries helping Taiwan defend itself.  Moreover, China throughout this century has made out-of-the-blue threats to incinerate America, most notably in October 2013. Then, the main outlets of Communist Party and state media — People’s Daily, China Central Television, and PLA Daily, among others — ran identical articles about how Chinese submarines launching ballistic missiles tipped with nuclear warheads could kill tens of millions of Americans, even listing the 11 cities they were targeting.   These articles were not the work of rogue journalists: They appeared across Chinese media at the same time, a clear indication they were directed from the top of the Chinese political system. Tellingly, the articles were run less than a year after Xi Jinping became the country’s ruler.   Putin had the opportunity to observe China’s nuclear threats. Would he actually pull the trigger himself? By now, he has made so many threats to do so that most observers believe he has just been bluffing.   Putin’s most recent threat came in response to the Biden administration allowing Ukraine to fire U.S.-made ATACMS missiles into Russian territory. Ukraine actually did so on Nov. 19, hitting an arms depot in the Bryansk region, about 70 miles inside Russia.  Moscow immediately called the United States a combatant in the war, and Putin, as noted, signed a decree lowering the threshold for the use of atomic weapons.  “We will only know for sure Mr. Putin isn’t bluffing when he actually explodes a nuclear weapon on our doorstep,” Peter Huessy of the National Institute for Deterrence Studies said to me after Ukraine’s launch of the ATACMS missiles. “But then it will be too late to finally take his threats seriously.”  Would China’s leadership be upset if Vladimir Putin carried through and detonated a nuclear device? And what is China’s position on the use of these weapons?  “China does not publish its true nuclear doctrine, which in reality is whatever advances the goals of the Chinese Communist Party,” Richard D. Fisher, Jr. of the International Assessment and Strategy Center told me in an e-mail message this month.  “In Ukraine, the Communist Party counsels ‘calm’ and ‘de-escalation’ in response to Russian nuclear threats, but the party would actually welcome any Russian nuclear strikes that sparked a larger European-U.S.-Russian nuclear disaster, as they would all emerge much weaker compared to China.”  “China then would be freer to start its own wars of aggression,” notes Fisher.  Gordon G. Chang is the author of “Plan Red: China’s Project to Destroy America” and “The Coming Collapse of China.” Follow him on X @GordonGChang.