Washington has ratcheted up war tensions in the Persian Gulf with an order to evacuate all non-essential US personnel from its embassy in Baghdad and its consulate in Erbil, the de facto capital of the Iraqi Kurdish region.

A State Department spokesman said the drastic action had been taken in response to “the increased threat stream we are seeing in Iraq,” but refused to provide any details on the supposed danger.

The US has carried out a massive military buildup in the region on the pretext of a supposed threat from Iran or so-called Iranian “proxies” among various Shia militia, from those organized in the Popular Mobilization Units (PMU) formed to fight ISIS in Iraq and now integrated into the Iraqi security forces, to those fighting ISIS in Syria, the Hezbollah movement in Lebanon and the Houthi rebels in Yemen.

A State Department spokesman told CNN Wednesday that “any attacks by the Iranian regime or its proxies against US interests or citizens will be answered with a swift and decisive US response.”

Sources in Baghdad reported that all day Wednesday helicopters were ferrying US personnel from the embassy on the Tigris River—the largest such US facility in the world—to a US military base at the Baghdad airport. The last time such an evacuation was ordered was in 2014 after ISIS had captured Mosul, Iraq’s second largest city, and appeared poised to march on Baghdad.

In the midst of this dramatic US action, the top British general deployed as part of “Operation Inherent Resolve” (OIR), the US-dominated intervention in Iraq and Syria, told Pentagon reporters that there was no increased threat to Western forces from Iranian-backed militias.

“There’s been no increased threat from Iranian-backed forces in Iraq and Syria,” said Maj. Gen. Christopher Ghika, the deputy commander of OIR in charge of intelligence and operations. “There are a substantial number of militia groups in Iraq and Syria, and we don’t see any increased threat from many of them at this stage.” Officially, these militias are on the same side as the US and NATO forces in fighting to defeat ISIS. In reality, the US is keeping 5,000 troops in Iraq and roughly 2,000 in Syria for the purpose of countering Iranian influence in the region.

Ghika’s statement undercut the justification being given for the US war buildup, which has seen the deployment off the Iranian coast of a battleship-carrier strike group, led by the USS Abraham Lincoln, and a bomber task force, including nuclear-capable B-52s. This has been followed by the dispatch to the region of the amphibious assault warship USS Arlington carrying US Marines, warplanes and landing craft, as well a Patriot missile battery.

Recent reports reveal that the Pentagon has drawn up battle plans calling for the shipping of as many as 120,000 US troops to the region in apparent preparation for an all-out war with Iran.

The British general’s statement provoked a highly unusual rebuke from the US Central Command, which oversees US military operations in the Middle East. A spokesman said that Ghika’s comments “run counter to the identified credible threats available to intelligence.” The statement, once again, failed to provide any details about these “threats.”

Equally significant was the response of the British Ministry of Defense, which backed up the general’s assessment, saying that “his comments are based on the day-to-day military operations.”

In the absence of any credible threat, the US evacuation from Iraq can have only one of two purposes. Either it is designed to increase tensions in the region and escalate military threats against Iran, or it is part of the preparations for an imminent direct US military assault on Iran, which would likely provoke retaliation by pro-Iranian militia elements inside Iraq.

In either case, the embassy evacuation is another provocative action by a US government that is relentlessly pursuing regime-change in Iran and is prepared to employ any pretext to further this aim.

Among these pretexts are the murky claims of acts of sabotage against four oil tankers off the coast of the United Arab Emirates (UAE) over the weekend. The US corporate media, acting as a pliant propaganda arm of the war build-up, has quoted unnamed US military officials attributing the alleged sabotage to Iran, while providing no evidence whatsoever to support this claim.

Iranian officials have countered that the alleged sabotage is likely the work of those seeking to provoke a US attack on Iran, including both Saudi Arabia and Israel, if not the special forces of the US itself. Foreign Minister Javad Zarif appeared alongside his counterpart in India and told the media that they had discussed “the suspicious activities and sabotage that are happening in our region.” He added, “We had formerly anticipated that they would carry out these sorts of activities to escalate tension.”

Tensions have been further escalated after a drone attack on pumping facilities of Saudi Aramco, the state-run energy company of Saudi Arabia’s ruling monarchy. The Houthi rebels in Yemen took responsibility for the action, which they said was in retaliation for the continuation of the near-genocidal US-backed war waged by Saudi Arabia against Yemen, which has killed some 80,000 civilians and brought 10 million to the brink of starvation.

In recognition of the war threat, Germany, which has 160 soldiers in Iraq, and the Netherlands, which has 169, suspended military training operations, citing the growing regional tensions. Along similar lines, Spain withdrew its frigate from the US carrier strike group dispatched to the Persian Gulf.

Another potential pretext for US military intervention is Iran’s nuclear program. One year ago, the Trump administration unilaterally tore up the nuclear accord signed in 2015 between Iran and six major powers—the US, China, Russia, Germany, France and the UK.

Iran has complied with a strict regime of restrictions and inspections of its nuclear program, but Washington has nevertheless re-imposed punishing economic sanctions, described by US officials as “maximum pressure” and tantamount to a state of war. The sanctions are aimed at reducing the country’s oil exports to zero and creating conditions of economic deprivation and chaos to facilitate a regime-change operation.

While the European powers—Germany, France and the UK—have formally declared their continued support for the nuclear accord, they have failed to mount any credible challenge to the US sanctions regime, depriving Iran of the promised benefits of the deal in terms of normalization of trade and investment.

In response, Tehran has suspended its commitments to cap production of enriched uranium and heavy water at its Arak facility for 60 days in an attempt to pressure the European powers to make good on their promises to launch an Instrument in Support of Trade Exchanges (INSTEX) to circumvent US sanctions by facilitating non-dollar trade with Iran.

While Iran’s actions still leave it in compliance with the Joint Comprehensive Plan of Action (JCPOA), the nuclear agreement signed by Tehran and the major powers in July 2015, and the Iranian government has consistently denied that it has pursued a nuclear weapon, the changes announced in relation to the nuclear program could be seized upon by Washington to justify a military attack.

Such a war of aggression would not only drag the entire region into a bloody conflict, it could become the antechamber of a third world war involving the US and its nuclear-armed “great power” rivals, Russia and China.