Elon Musk's recent pronouncements on major foreign policy issues are ratcheting up national security concerns about his takeover of Twitter, a global speech platform used by hundreds of millions, 75 percent of them outside the United States.

In the 10 days since Elon Musk agreed again to buy the social media platform, he has proposed solving the war in Ukraine by letting Russia keep territory and won praise from a top Chinese diplomat for suggesting China take control of Taiwan. On Friday, U.S. and Ukrainian officials were sent scrambling as news broke that Musk had asked the Pentagon last month to take over paying for his Starlink satellite communications service in Ukraine.

Musk complained that he could not shoulder the costs and keep sending new terminals to Ukraine, even though many have been subsidized by the U.S. and other nations. Ukraine quickly noted the critical nature of Musk's contributions.

Musk's attempts to shape foreign policy in 280 characters or less have raised new fears about how he will wield the platform's outsize influence over politicians and global leaders who rely on Twitter if he takes control of the company.

Since autocrats already use the platform to spread lies about opponents and whip up violence and mayhem, Musk's pursuit of approval from two of the most powerful is especially unnerving.

"It's a very good illustration as to why it would be a disaster if Musk does come to own Twitter," said Paul Barrett, deputy director of New York University's Stern Center for Business and Human Rights. "You could have provocations, whether engineered by Musk himself or by others, that could have global implications."

The latest scrutiny began this week when prominent geopolitical analyst Ian Bremmer said Musk had been speaking with Russian President Vladimir Putin before tweeting out a three-point plan for Ukraine that would leave Crimea, taken by force in 2014, in Russia's hands.

"I spoke with Elon two weeks ago, and he told me Putin (in a direct conversation with him) was 'prepared to negotiate' . . . and had outlined the minimum the Russian president would require to end the war," Bremmer wrote to newsletter subscribers.

As word spread on a second day of intensive Russian attacks on civilian population centers in Ukraine, law professors speculated on whether Musk should have registered as a foreign agent.

"Logan Act" became one of Twitter's trending topics in the country, referring to the 223-year-old law that bars private citizens from conducting foreign policy.

Only then did Musk deny having spoken to Putin, since a conversation a year and a half ago about space issues.

Bremmer, a Time magazine columnist and author as well as head of the Eurasia Group consultancy, stood by his account, tweeting that "Elon Musk told me he had spoken with Putin and the Kremlin directly about Ukraine. he also told me what the Kremlin's red lines were."

Four days earlier, Musk said in a Twitter conversation that he was in touch with "quite a few" parties in the war.

The exchange has left lawmakers questioning the nature of Musk's communications with Putin.

"Clearly, it's something we should keep an eye on," Rep. John Katko (N.Y.), the top Republican on the House Homeland Security Committee, said during a Post Live interview on Thursday.

The argument over whether Bremmer was mistaken, Musk had been exaggerating, or Musk was backtracking from the truth failed to obscure two deeper points Bremmer made in his newsletter:

First, given opposition to aiding Ukraine among some Republicans, Musk's Twitter takeover and the likely reinstatement there of former president Donald Trump and some of his allies would spread opposition further and divide the country, threatening Ukraine's backup.

Second, Musk's acquisition would pit his new, free-speech business against his old businesses: SpaceX, which relies on the Pentagon and NASA, and Tesla, which relies on China for scarce physical resources.

"Each of these three are huge bets on completely different futures for a technopolar world. They're also the most geopolitically opposed business models I've ever seen a single person pursue. Or maybe it's the world's biggest hedge," Bremmer wrote.

Bret Schafer, a senior fellow at the German Marshall Fund's Alliance for Securing Democracy, said Musk's communications with Chinese and Russian officials and business interests abroad will create unprecedented dilemmas if he closes his deal to buy Twitter.

"Most owners of these platforms have had to remain neutral on issues related to politics and geopolitics," Schafer said. "His freewheeling style of communicating with authoritarians is certainly going to create challenges with how the platform is perceived."

Though Musk has said he will rid Twitter of automated bots, Schafer said there has been little clarity around how Musk would respond to other types of foreign influence operations. He said it is unclear how Musk would handle a Russian hack and leak operation, such as occurred in the run-up to the 2016 presidential election, or whether Chinese government officials should be allowed to join a platform that citizens cannot access. A Saudi prince is planning to keep a stake in Twitter as the deal closes, even though a former Twitter employee was convicted of spying on dissidents for the Saudi government.

In recent years, major social media companies "have taken a stand on the side of democracy over autocracy," Schafer said. "It will be interesting to see what direction that shifts in if and when Musk takes over."

Because Twitter is much smaller than other social networks such as Facebook and YouTube, Musk will have a greater ability to micromanage content moderation decisions and dealings with foreign leaders than executives at other social networks, said Rose Jackson, the director of the Democracy and Tech Initiative at the Atlantic Council. Yet despite Twitter's smaller size, it wields immense influence over key decision-makers in media and politics, creating unique national security risks.

Jackson said that the Committee on Foreign Investment in the United States, a cross-government group that reviews foreign transactions involving American firms, "probably isn't sufficient" in addressing the national security risks presented by the Musk deal.

"It brings to the fore whether we have sufficient tools to address genuine national security risks and how tech companies, and particularly information tech companies, are financed," said Jackson, a former entrepreneur and State Department official.

What worries many about Twitter is that the lion's share of Musk's wealth is his stake in Tesla, so that in any conflict among worldviews, the platform would be most likely to suffer.

Tesla had record sales of its vehicles in China in September, even as its competition with local electric vehicle makers intensifies.

And Twitter already has issues with China potentially gathering information about its critics through advertising and spying, according to a recent whistleblower complaint and testimony by former security chief Peiter Zatko. He said the FBI warned the company that a Chinese intelligence operative was working there.

After Musk's Ukraine tweet a week ago, a commentator for the Chinese Communist Party's Global Times cited it and wrote to a half-million Twitter followers that Musk "believes too much in the U.S. and West's 'freedom of speech.' He will be taught a lesson."

Within days, Musk opined in a Financial Times interview that Taiwan should be governed like Hong Kong, winning praise from China's ambassador to Washington: "I would like to thank @elonmusk for his call for peace across the Taiwan Strait and his idea about establishing a special administrative zone for Taiwan."

Barrett and others said they were not afraid of Musk bringing Twitter to China and back into Russia, saying that could help citizens communicate more.

Instead, they fret that a Twitter without much moderation would allow propagandists for those governments to wreak more havoc than they already do.

"Elon Musk is entitled to his opinions and speech, but let's just say Freedom House would welcome the opportunity to brief him more thoroughly on the egregious human rights violations in Russia, China and elsewhere in the world before he takes ownership of one of the largest tech platforms," said Michael Abramowitz, president of the nonprofit Freedom House, which tracks rights globally.

"Ukrainians are fighting to protect their fundamental freedoms. Taiwan is a democracy where people enjoy those freedoms every day, and they know the threat they are facing from the PRC. We believe that all democracies and democracy-supporting businesses should support and defend these freedoms globally."

Accountable Tech, a left-leaning group that has advocated for regulation of tech giants, sent a letter last week to congressional leaders that called for an investigation into Musk's relationships with foreign actors. The letter says Congress should use its subpoena powers to determine whether Musk is in communication with senior officials at the Kremlin or in China "who could use this acquisition to undermine American national security interests."

"It is critical that Congress immediately investigate the national security implications of this acquisition and take steps, as necessary, to protect American democracy and independence," the group's leaders, Nicole Gill and Jesse Lehrich, wrote.