Washington DC is still digesting a serious security breach at the heart of the Trump administration.

It's the story of how a journalist - the Atlantic magazine's Jeffrey Goldberg - was added to a Signal platform messaging group which apparently included Vice-President JD Vance and Defence Secretary Pete Hegseth, in addition to National Security Adviser Mike Waltz.

The topic being discussed was attacking the Iran-backed Houthi group in Yemen.

Goldberg said he had seen classified military plans for the strikes, including weapons packages, targets and timing, two hours before the bombs struck.

What are the main revelations in a nutshell?

Vance questions Trump's thinking

On the military action, Goldberg reported that the account named JD Vance wrote: "I think we are making a mistake."

The vice-president said targeting Houthi forces that are attacking vessels in the Suez Canal serves European interests more than the US, because Europe has more trade running through the canal.

Vance added that his boss was perhaps unaware of how US action could help Europe.

"I am not sure the president is aware how inconsistent this is with his message on Europe right now," Vance said. "There's a further risk that we see moderate to severe spike in oil prices."

The vice-president went on to say, according to Goldberg, he would support the consensus but would prefer to delay it by a month.

Goldberg reported in his article that spokesman for JD Vance had later sent him a statement underlining that Trump and Vance had had "subsequent conversations about this matter and are in complete agreement".

Since coming to power, Trump has castigated his European Nato allies, urged them to increase defence spending and generally insisted that Europe needs to take responsibility for protecting its own interests.

Blame for 'free-loading' Europe

Arguments over why the US could - and should - carry out the military strike against the Houthis did not sway Vance.

He said to the defence secretary, "If you think we should do it let's go. I just hate bailing Europe out again."

Hegseth reciprocated:

"I fully share your loathing of European free-loading. It's PATHETIC."

A group member, only identified as "SM" suggested that after the strike, the US should "make clear to Egypt and Europe what we expect in return".

"If Europe doesn't remunerate, then what?" he asked.

"If the US successfully restores freedom of navigation at great cost there needs to be some further economic gain extracted in return," the user continues.

After the strike: Emojis and prayers

According to Goldberg, the US national security chief posted three emojis after the strike: "a fist, an American flag, and fire".

The Middle East special envoy, Steve Witkoff, responded with five emojis, Goldberg said: "two hands-praying, a flexed bicep, and two American flags".

Secretary of State Marco Rubio and White House chief of staff Susie Wiles voiced messages of support, he said.

"I will say a prayer for victory," Vance said as updates on the strikes were given.

Two others members added prayer emojis, Goldberg reported.

Controlling the message: Blame Biden

To Vance's concerns that the action may be seen as going against Trump's message on Europe, the US defence secretary wrote:

"VP: I understand your concerns – and fully support you raising w/ POTUS [Trump]. Important considerations, most of which are tough to know how they play out (economy, Ukraine peace, Gaza, etc).

"I think messaging is going to be tough no matter what – nobody knows who the Houthis are – which is why we would need to stay focused on: 1) Biden failed & 2) Iran funded."

The Trump administration has consistently blamed Joe Biden for being too lenient with Iran.

Waltz in the spotlight

Goldberg said he got an unsolicited invitation on the Signal messaging platform on 11 March by an account named Michael Waltz and was then added to the group chat about Yemen two days later.

The president was not part of this group, but Trump's closest collaborators were.

Goldberg initially thought this was a hoax, but soon realised it was real.

The whole issue is adding pressure on the national security adviser, with Democrats in the House and Senate calling for an urgent inquiry.

When asked on Monday about the whole incident, Trump said he didn't know anything, but he has stood by Waltz.

The defence secretary has also said no secrets were revealed.

"Nobody was texting war plans," he told journalists.