The United States directly warned Tuesday that it would target Chinese firms or people involved in any effort to send lethal aid to Russia for its war in Ukraine, underscoring a fast-deepening showdown with its superpower rival.

In the most specific public admonition on the issue to Beijing so far, US Secretary of State Antony Blinken underlined that arming Moscow’s forces would cause China serious problems around the world.

“China can’t have it both ways when it comes to … the Russian aggression in Ukraine. It can’t be putting forward peace proposals on the one hand, while actually feeding the flames of the fire that Russia has started with the other hand,” Blinken said in Kazakhstan.

US officials have spent the past 10 days warning that it has intelligence that China is considering sending lethal aid to Russia, causing fury in Beijing and underscoring how already deteriorating diplomatic relations are being rocked by almost daily crises – from a recent spy balloon controversy to a revived dispute over the specific origins of Covid-19. On Monday evening, the White House gave federal agencies a 30-day deadline to remove TikTok, which is owned by Chinese company ByteDance, from federal devices. And later Tuesday, a new House select committee will hold its first hearing on the fast-widening US-China rivalry.

In his clearest comments about how the US would respond if China did decide to help its ally Russia with lethal aid, Blinken spoke of punishments for Chinese firms that could cause Beijing to pay an economic price.

“We did very clearly warn China about the implications and consequences of going through with providing such support,” referring to his own meeting with top Chinese diplomat Wang Yi in Munich this month and President Joe Biden’s talks with President Xi Jinping in Indonesia in November 2022.

“We will not hesitate, for example, to target Chinese companies or individuals that violate our sanctions, or otherwise engaged in supporting the Russian war effort,” he said.

New confrontations – along with rising tensions between US and Chinese forces in Asia and escalating standoffs over Taiwan – are dramatizing a long-building and once theoretical superpower rivalry that is suddenly a daily reality.

This increasingly adversarial relationship touches multiple areas of American life – from the economy to public health. It spans the challenges faced by the US military, which are amid the great geopolitical clashes of the early 21st century like in Ukraine to risks posed by the Chinese-designed apps on the electronic devices everyone carries everywhere. It’s fueling the dangerous possibility that the US and China are locked into a potentially disastrous slide toward conflict. And it poses serious challenges for a polarized US political system that struggles to have a rational debate on these issues without descending into a partisan game of who can be tougher on China. Such one-upmanship only deepens a self-perpetuating cycle of escalation between the two sides.

It is in this politicized atmosphere that the GOP-controlled House is debuting a new bipartisan select committee on competition with China during a primetime hearing on Tuesday night, just as Washington-Beijing tensions have rarely been worse.

The committee’s work will be based on the premise that after years of trying to integrate China peacefully into the global system as a competitor not an enemy, the US is switching to a tougher stance in a belief that a new generation of Chinese leaders is trying to dismantle the US global order and international law.

Republican Rep. Mike Gallagher, the new committee’s chairman, told CNN’s Manu Raju that Tuesday’s hearing would not focus specifically on the latest drama – after the Department of Energy assessed with low confidence that the Covid-19 pandemic originated with a lab leak in the Chinese city of Wuhan. He said that finding, which is a minority view among US intelligence agencies, could be examined in a future hearing but that he wanted to show Americans on Tuesday that the threat from China was “not just an over there problem, it’s … right here.”

“We want to understand what we got wrong about the Chinese Communist Party and what we need to understand about it going forward in order to get our policy right,” the Wisconsin Republican said.

On CBS News on Sunday, Gallagher warned: “We may call this a strategic competition, but it’s not a tennis match. This is about what type of world we want to live in. Do we want to live in Xinjiang-lite or do we want to live in the free world?” he said, referring to the Chinese region where the US has accused China of inflicting genocide on the Uyghur minority, a charge China continues to vehemently deny.

The committee may be one of the few areas where a divided Congress – and potentially the White House – can find common ground. The Biden administration has reinforced the already tough stance toward China that ex-President Donald Trump adopted later in his presidency. Biden, for instance, last year signed a new law that will allow the government to spend $200 billion in a bid to claim the leadership of the semiconductor chips industry – a critical sector that could decide the economic race between the US and China in decades to come.

The new controversy over the origins of Covid-19 is a study in isolation of many of the forces ripping at US-China relations, including US mistrust of the Chinese Communist Party and its leader Xi Jinping’s desire to preserve his prestige and that of a political system he holds up as an alternative to Western democracy. US demands for information about the origins of the pandemic show how China is refusing to play by global rules – in this case, in allowing follow-up virological investigations. All of this only exacerbates intense reaction in Washington, and in turn tears at US political fault lines.

There is no consensus within the US government on the origins of the pandemic. Intelligence agencies remain divided over whether it started with animal to human transmission in a Wuhan wet market or originated in a viral leak from a Chinese laboratory – and no new evidence has emerged publicly in support of the lab leak theory. Investigating the origins is hugely important.

“There is a bottom line here, which is that neither lab leak, nor spillover – i.e. animal origin – can be ruled out. We don’t have definitive information,” Tom Frieden, the former director of the US Centers for Disease Control and Prevention, told CNN on Monday.

But it didn’t take long for Republicans to claim political victory in the wake of Sunday’s Wall Street Journal report about new intelligence causing the Department of Energy to believe with low confidence that a lab leak was to blame. Georgia Rep. Marjorie Taylor Greene, who has been accused of spreading conspiracy theories about the pandemic, tweeted, “Conspiracy theorists - 100 Media - 0.”

Republican Sen. Tom Cotton of Arkansas tweeted: “Re. China’s lab leak, being proven right doesn’t matter. What matters is holding the Chinese Communist Party accountable so this doesn’t happen again.”

Such definitive statements, based on one assessment, do not recognize that the US intelligence community is still divided over the matter. Some Republicans have long sought to prove that the virus was a conspiracy by China to unleash contagion on the world, and many have long appeared to be seeking an explanation for the pandemic that could mask Trump’s negligence in handling it.

But even if the virus did emerge from a laboratory, it doesn’t mean it was necessarily man made or that the rest of the world was deliberately exposed.

China’s foreign ministry reacted angrily to the reemergence of the lab leak theory in Washington, warning that Americans should “stop stirring up arguments about laboratory leaks, stop smearing China and stop politicizing the issue of the virus origin.”

In many ways, it doesn’t matter if poor security at a lab in China or animal transmission caused the pandemic that killed nearly seven million people globally, according to World Health Organization figures, and more than a million in the US. Both possible routes of transmission represent a threat to humanity and need to be addressed, which is one reason why China’s lack of transparency on the issue is so potentially dangerous. The pandemic remains a huge embarrassment for China, souring its national mythology of a mighty rising power.

But in Washington this week, the issue has again degenerated into an excuse for Republicans to target scientists and government health experts and to twist a narrative about Covid-19 that still has massive gaps.

The challenge for the new select committee, which is especially probing economic and technological competition with China, will be to break this cycle of politicization to provide a useful examination of US-China relations that could result in effective policy recommendations down the road.

Another example of how the wider antagonism between the United States and China is coloring other crises is evident with Ukraine.

The US, citing unpublished intelligence, has spent the last week warning that China is considering sending lethal aid to bolster Russia’s forces – a situation that would effectively put China on the opposite side of a proxy war with the US and NATO powers that have sent billions of dollars in weapons to Ukraine.

Beijing has long amplified Russia’s justifications for the invasion, which took place a year ago shortly after Russian President Vladimir Putin traveled to the Chinese capital to agree to a friendship with “no limits” with Xi. China would prefer Russia, which shares its autocratic form of government, not to suffer a total defeat in Ukraine – which could lead to the ousting of close ally Putin. And China increasingly tends to view its global interests through the prism of its standoff with the US, so it may perceive an advantage in Washington being locked in an arms-length conflict in Ukraine that is costing billions of dollars and to which it is sending reserve military equipment and ammunition that can therefore not be used to bolster its Pacific forces. Delays in procurement in the US arms industry caused by Ukraine could also slow the flow of weapons to Taiwan.

Yet a decision by China to throw in its lot with Russia in Ukraine would amount to a radical change in foreign policy – and another massive plunge in US-China relations. Washington and the European Union would certainly respond with sanctions on Chinese firms, a threat that will likely give leaders in Beijing pause, as the country’s economy slowly recovers from years of Covid isolation.

“China has never had to incur any costs for its support for Russia. This (would be) the first time – it is a very important crossroads,” Andrea Kendall-Taylor, a former deputy national intelligence officer for Russia and Eurasia at the National Intelligence Council, said on CNN Monday.

As with the latest Covid-19 drama, China has reacted angrily to US criticism – all of which it appears to view in the wider context of its belief that every US policy is aimed at depriving it of its rightful global influence.

This new front in US-China antagonism is also beginning to seep into US politics. While being tough on Beijing is a bipartisan position, the idea of a broadened conflict in Ukraine conflicts with the more limited view of US power projection abroad among “America First” Republicans. Traditional hawks like Senate Republican leader Mitch McConnell strongly support even more US aid for Ukraine, but some conservatives like Florida Gov. Ron DeSantis – a likely 2024 contender – have warned against escalating conflict. In a rare foreign policy comment last week, he specifically mentioned potential Chinese involvement.

“I don’t think it’s in our interest to be getting into a proxy war with China, getting involved over things like the Borderlands or over Crimea,” DeSantis told “Fox & Friends,” referring to Ukrainian lands Russia has seized with military force.

His comments were a reminder that everything in Washington is ultimately political. And few issues are as politicized as tortured US relations with China.

CNN’s Jennifer Hansler contributed to this report.