With a deadly missile strike against an Iranian-backed Iraqi militia position on the Syria-Iraq border Friday, the Biden administration has spelled out in blood the real meaning of the Democratic president’s incessant declarations that “America is back.”

The attack, executed in blatant violation of international law and with no legal authorization from the US Congress, signals that the Biden White House is embarking upon a highly aggressive American foreign policy, escalating the militarism and confrontations pursued by its predecessor, in the Middle East and internationally.

According to Syrian medical sources quoted by Reuters, the US air raid, carried out at dawn on Friday, killed at least 17 Iraqi militiamen. The UK-based Syrian Observatory for Human Rights reported that the strike had killed 22 fighters from the Hashed al-Shaabi, or Popular Mobilization Forces, an official arm of Iraq’s military, which was sent into Syria to combat ISIS. More fighters were wounded, and the death toll is likely to rise.

Ostensibly, the missile strike was in retaliation for a February 15 rocket attack on a US base in Iraqi Kurdistan’s capital Erbil that killed a single Syrian contractor. There is no evidence that the attack on the US base was the work of the Iranian-backed militia that the US struck on Friday, which had not only denied responsibility, but denounced the attack on the Erbil base.

Pentagon officials indicated that President Joe Biden was given a menu of targets and levels of US military destruction to choose from and signed off on the Syria missile strike.

Asked on Friday what “message” Biden was sending with the strike, Pentagon spokesman John Kirby told MSNBC television news, “The message is clear and unambiguous; we’re going to protect our national interests in the region.”

The decision to attack Syria has unmistakable strategic significance. It marks the first time that the US has attacked targets in the war-ravaged country since December 29, 2019, when Donald Trump ordered an air strike, also ostensibly in response to a rocket attack on a US base in Iraq.

Five days later, on January 3, 2020, Washington carried out the drone missile assassination of Iranian Revolutionary Guard Gen. Qassem Suleimani, considered the second-most important political figure in Iran. The missile attack marked a dramatic escalation of the Trump administration’s “maximum pressure” campaign against Iran.

Washington backed down from the confrontation, which had brought the Middle East, and potentially the entire planet, to the brink of a catastrophic new war that would have rapidly eclipsed the death and devastation wrought by the decades-long US interventions in Iraq and Afghanistan.

The strike ordered by Biden marks an end to the little more than a year-long pause in US air strikes in Syria that followed the Suleimani assassination. This has been a year in which the US has been dominated by the criminal policy that has led to over half a million COVID-19 deaths, as well as by a bitter internecine struggle within the US ruling political establishment leading to two impeachments of Trump. Much of that conflict centered on differences over foreign policy, with Democrats denouncing Trump for being too “soft” on Russia and China, both nuclear-armed powers.

The attack in Syria is widely and rightly seen as a dangerous escalation of US aggression that can once again threaten a regional and even global conflagration. It is a concrete manifestation of the shift in policy that is developing under the new Democratic administration.

The Syrian government denounced the missile strike as an act of “cowardly US aggression” and accused the Biden administration of following the “law of the jungle.” Russian, Chinese and Iranian officials also condemned the attack.

The one source of international praise for the US attack was Israel, which has carried out its own airstrikes against Syria while generally refusing to confirm or deny its responsibility. “The Iranians didn’t realize that Biden is not Obama, and that if they will continue down this road of miscalculation they will eventually get hit,” an unnamed senior Israeli official told the Walla news website.

Iran is among the most immediate targets of Friday’s missile strike. The Biden administration came into office vowing to rejoin the Joint Comprehensive Plan of Action (JCPOA), the 2015 agreement struck between Iran and the major powers in which Tehran traded sharp restrictions on its civilian nuclear program for the lifting of punishing economic sanctions. Trump abrogated the agreement in 2018, launching a “maximum pressure” campaign of redoubled unilateral sanctions tantamount to a state of war.

Washington has made no move to lift these sanctions—nor, for that matter, any of the others inflicted by the US upon countries constituting over one third of humanity—since Biden’s inauguration. Instead, the US has insisted that Tehran first return to full compliance with the terms of the JCPOA, rolling back limited increases in its enrichment of uranium carried out in response to Washington's ripping up of the deal and the failure of the European powers to effectively challenge American sanctions.

Biden’s secretary of state, Antony Blinken, has repeatedly declared that any agreement with Iran will have to be “longer and stronger” than what was negotiated when Obama was in office. In addition to imposing permanent restrictions on Iran’s nuclear program, this means the dismantling of Iran’s conventional missile program as well as the rolling back of its influence throughout the Middle East. What Washington wants is to return Iran to the status of a defenseless semi-colony. The attack on Syria is an opening salvo in a renewed campaign of aggression to achieve this aim.

The Syrian missile strike was also aimed at both Russia and China and their influence in the region. China, identified by the Biden administration as Washington’s number one “strategic competitor” and the target of “extreme competition,” after two decades of US imperialist military interventions in the Middle East, has emerged as the region’s largest investor and the top trading partner for many of its countries.

It is more than a coincidence that the latest US missile strike in Syria comes in the immediate wake of joint exercises by Iranian, Russian and Chinese warships in the strategic waters of the Indian Ocean. The last such exercise, the joint Iranian-Russian-Chinese “Maritime Security Belt” naval drills, was held in December 2019, on the eve of the murder of Suleimani.

Even as Washington is escalating its aggression in the Middle East, the Pentagon is staging provocative naval exercises in the South China Sea and Taiwan Strait, while directly threatening Russia with the deployment of B-1 bombers in Norway.

The missile strike also serves as a shot across the bow of Washington’s erstwhile NATO allies, particularly Germany and France. This follows the noticeably cool reception by Chancellor Angela Merkel and President Emmanuel Macron to Biden’s speech to the Munich Security Conference last week, in which he proclaimed not once, but three times, that “America is back,” while demanding that the European imperialist powers subordinate themselves to US interests.

The attack on Syria received broad support within the Democratic Party leadership and was praised by leading Republicans. Representative Michael McCaul, the top Republican on the House Foreign Affairs Committee, declared, “Responses like this are a necessary deterrent and remind Iran, its proxies and our adversaries around the world that attacks on US interests will not be tolerated.”

The attack has made clear that agreement on escalating military aggression to offset the decline of US imperialist global hegemony will serve as the foundation for the Biden administration’s pursuit of “bipartisan unity” with the fascistic elements within the Republican Party who sought to overturn his election.

There is also a powerful domestic political motive for the escalation of US militarism. This is the need to divert outward the immense and unsustainable social contradictions of American capitalism.

The crisis of US and world capitalism is producing not only a drive to war, but also an international upsurge in the class struggle in the face of the mass death produced by the murderous pursuit of a herd immunity policy in response to the COVID-19 pandemic, the continuous growth of social inequality and escalating attacks on basic social and democratic rights.

It is only this struggle that can provide the foundation for genuine opposition to the war drive of US and world imperialism. The urgent task is the building of an international and socialist movement in the working class to end the threat of world war by overthrowing the capitalist system which is its source.