The world’s richest man wants the West to more seriously consider the risk of nuclear conflict and World War III breaking out over Ukraine, as Russia’s hold over Crimea—illegally annexed by Russia in 2014—is thrown into question.

“If Russia is faced with the choice of losing Crimea or using battlefield nukes, they will choose the latter,” Elon Musk wrote in a tweet on Monday.

He continued: “We’ve already sanctioned/cutoff Russia in every possible way, so what more do they have left to lose? If we nuke Russia back, they will nuke us and then we have WW3.”

https://twitter.com/elonmusk/status/1581989915491172353

Russia’s war in Ukraine is now inching toward its eighth month, far longer than Russian President Vladimir Putin expected. His army is up against largely unified support for Ukraine among Western nations, as well as a dogged Ukrainian counteroffensive that has made steady but significant gains in reclaiming annexed territory in recent weeks.

The threat of a drawn-out war in Ukraine has pushed Putin to escalate his rhetoric, authorizing the mobilization of 300,000 additional troops and making multiple nuclear threats.

Some experts fear that Russia’s nuclear arsenal could be the powder keg behind a third global war. And with the war showing signs of intensifying after a strategic bridge linking Russia to the Crimean Peninsula was bombed this month, Musk says that moment could be even closer than first thought.

Musk and Ukraine

Earlier this month, Musk, CEO of Tesla and SpaceX, made waves when he suggested that the two sides reach a compromise before the use of nuclear weapons escalates the conflict into World War III.

He did so by sharing his view on what a peaceful resolution in Ukraine would look like, including Ukraine remaining neutral and permanently ceding control of Crimea to Russia.

In his proposal, Musk wrote that this outcome was “highly likely,” and the only question was “how many die before then.” He noted at the time that a nuclear escalation was a “possible, albeit unlikely” outcome.