ST PETERSBURG, RUSSIA 7 JUNE 2019: China’s President Xi Jinping (L) and Russia’s President Vladimir Putin at a plenary meeting of the St. Petersburg 2019 International Economic Forum (SPIEF).

Sergei Bobylev | TASS | Getty Images

President Joe Biden faces a nightmare scenario of global consequence: intensified Sino-Russian strategic cooperation to undermine US influence and strengthen Biden’s efforts to rally democratic allies.

It is the most significant and least recognized test of Biden’s leadership to date: it could be the defining challenge of his presidency.

Over the past week, Russia and China have simultaneously escalated their separate military activities and threats to the sovereignty of Ukraine and Taiwan, respectively – countries whose living independence is an affront to Moscow and Beijing but at the center of the interests of the US and its allies in theirs Regions stands.

Even if the actions of Moscow and Beijing do not lead to a military invasion of either country, and most experts still consider this unlikely, the scale and intensity of the military measures require immediate attention. US and Allied officials dare not deny the certainty that Russia and China are exchanging information or the growing likelihood that they will increasingly coordinate actions and strategies.

“The [Russian] The build has reached the point where it could provide the basis for a limited military incursion, “Central Intelligence Agency director William J. Burns told the Senate Intelligence Committee this week. Allies must take it very seriously.”

Regarding China, the secret services’ annual US threat assessment states: “China is trying to exploit doubts about US commitment to the region, undermining Taiwan’s democracy and expanding Beijing’s influence.” A warning of “Russia’s growing strategic cooperation with China – to achieve its goals” was lost in media coverage of the report.

Viewed independently, the challenges in China and Russia would be a handful for any US president. Should China and Russia act more coherently and coherently and you should have a narrative that is more consistent than the plot of a Tom Clancy novel. It is a scenario for which the US and its allies lack a strategy or even a common understanding.

For anyone who has doubts about Sino-Russian ambitions, the Global Times is one of my favorite places to read Chinese tea leaves, often a mouthpiece for Beijing’s leadership. In an editorial late last month, under the headline “China-Russia Relations Deepen as the US and Its Allies Fight”, he wrote: “The most influential bilateral relationship in Eurasia is China-Russia’s broad strategic coordination partnership for a new one Era.”

In a barely veiled warning to Japan and South Korea, it says: “China and Russia understand the weight of their relationship … To be honest, no country in the region can stand alone against China or Russia, let alone fight against the powers that be at the same time. It would be disastrous for any country that tends to confront China and Russia by forming an alliance with the US. “

Russian leader Vladimir Putin, who was asked last October about the possibility of a formal military alliance with China, said: “In theory it is entirely possible.”

In any case, there is nothing theoretical about the military escalations in Ukraine and Taiwan.

Last week, Russia amassed the largest concentration of troops along the Ukrainian border since annexing Crimea in 2014. According to Ukrainian government officials, Russian President Vladimir Putin has brought more than 40,000 soldiers near Ukraine’s eastern border to conduct “combat training exercises” over a border period of two weeks.

At the same time, China has taken its military overflights into Taiwan’s air defense zone to unprecedented levels after flying more than 250 sorties near the island this year. The Chinese military sent 25 fighter jets to Taiwan last Monday, a record high since Taiwan announced figures last year.

The Biden government responded to Putin this week with the carrot of a summit and the rod of new sanctions. On Tuesday, Biden called Putin signaling that he would not try to escalate tensions with the leader, whom he had agreed to be a “killer” just a month ago.

On Wednesday, US Secretary of State Antony Blinken stood next to NATO Secretary General Jens Stoltenberg as they condemned Russia’s military build-up. The Biden government’s strongest reprimand came Thursday when it announced new economic sanctions against 38 Russian entities accused of electoral disruption and cyberattacks, expelled ten diplomats, and introduced measures to keep U.S. financial institutions trading in newly issued Russian government bonds and bonds prohibited.

China’s raids on Taiwan came soon after the State Department issued guidelines relaxing the rules for US government officials working with Taiwan. Blinken said the government is concerned about China’s “increasingly aggressive actions” and is committed to ensuring that Taiwan “has the ability to defend itself.” The United States demonstrated its support for Taiwan on Wednesday by sending an unofficial delegation consisting of a former US Senator and two former US Assistant Secretary of State to Taiwan.

This unfolding great power drama couldn’t come at a worse time for the Biden government, whose officials won’t reach their 100-day term until April 30. However, this is likely the point for Russian leader Vladimir Putin and Chinese President Xi Jinping as they try to gain an edge before Biden can move to a safer post by reviewing policy and filling senior leadership positions.

These real events also complicate the Biden administration’s carefully crafted plans to methodically order its actions, and reasonably argue that US renewal is a prerequisite for effective global governance.

Biden’s goal is to suppress Covid-19 through accelerated vaccine distribution, increase economic dynamism and competitiveness through $ 4 trillion in stimulus and infrastructure spending, and restore relationships with key allies, a goal that Biden’s meetings with the Japanese Prime Minister Suga this week reflected Yoshihide.

The Biden administration faces a number of other foreign policy challenges at the same time, from the president’s announcement this week to withdraw US troops from Afghanistan by September 11, to efforts to keep nuclear talks with Iran despite the attack to resume facility on Tehran’s nuclear enrichment facility in Natanz last Sunday.

That’s a lot that every new president has to deal with. However, how skillfully Biden approaches the combined, growing challenge from Russia and China will shape our era.

Frederick Kempe is a best-selling author, award-winning journalist, and President and CEO of the Atlantic Council, one of America’s most influential think tanks on global affairs. He worked for the Wall Street Journal for more than 25 years as foreign correspondent, assistant editor-in-chief and senior editor for the European edition of the newspaper. His latest book – “Berlin 1961: Kennedy, Khrushchev, and the Most Dangerous Place in the World” – was a New York Times bestseller and was published in more than a dozen languages. Follow him on Twitter @FredKempe and subscribe here to Inflection Points, his view every Saturday of the top stories and trends of the past week.

More information from CNBC staff can be found here @ CNBCopinion on twitter.