(From left) JD Vance, Pete Hegseth and Mike Waltz were among 18 high-ranking individuals who discussed extremely sensitive material on the private messaging app Signal. Photograph: Evelyn Hockstein/Reuters

It is jaw-dropping that senior Trump administration figures would accidentally leak war plans to a journalist. But the fundamental issue is that 18 high-ranking individuals were happy discussing extremely sensitive material on a private messaging app, highlighting the administration’s extraordinary amateurishness, recklessness and unaccountability.

The visceral hostility to Europe spelt out again by the vice-president, JD Vance, was glaring. So was the indifference to the potential civilian cost of the strikes on Houthi targets in Yemen, designed to curb attacks on Red Sea shipping. The Houthi-run health ministry said that 53 people including five children and two women were killed. The response by the national security adviser, Michael Waltz, to the attacks was to post emojis: a fist, an American flag and fire. The lack of contrition for this security breach is also telling. Individually and together, these are far more than a “glitch”, in Donald Trump’s words. They are features of his administration.

Mr Waltz appears to have organised the Signal chat and inadvertently added Jeffrey Goldberg, editor in chief of the Atlantic. The magazine says that the secretary of defence, Pete Hegseth, posted details of the timing and sequencing of attacks, specific targets and weapons systems used, though the administration denies that classified information was shared. Other members included Mr Vance; the director of national intelligence, Tulsi Gabbard; the CIA director, John Ratcliffe; Steve Witkoff, special envoy to the Middle East; and “MAR”, the initials of the secretary of state, Marco Rubio.

These conversations would normally take place under conditions of high security. While Signal is encrypted, devices could be compromised. Foreign intelligence agencies will be delighted. Legal experts say using Signal may have breached the Espionage Act.

The hypocrisy is glaring. Mr Trump’s first presidential campaign – and several members of this Signal group – lambasted Hillary Clinton for using a private email server to receive official messages that included some classified information of a far less sensitive nature, and for the autodeletion of messages. These Signal messages too were set to disappear, though federal records laws mandate the preservation of such data.

In many regards, this leak hammers home what US allies already knew, including this administration’s contempt for Europe, which the chat suggests will be expected to pay for the US attacks. The vice-president characterised an operation carried out to safeguard maritime trade and contain Iran as “bailing Europe out again”. Mr Hegseth responded that he “fully share[d] your loathing of European free-loading”. Concerns about information security are familiar territory too. In his first term, the president reportedly shared highly classified information from an ally with Russia’s foreign minister, and after leaving office he faced dozens of charges over the alleged mishandling of classified material, before a judge he had appointed threw out the case against him.

The UK and others cannot simply walk away when they are so heavily dependent on and intermeshed with US intelligence capabilities. Their task now is to manage risk and prepare for worse to come. It may be that this breach is not chiefly distinguished by its severity, but by the fact that we have learned about it.

Editorial, The Guardian

Do you have an opinion on the issues raised in this article? If you would like to submit a response of up to 300 words by email to be considered for publication in our letters section, please click here.