The telephone calls and WhatsApp messages continue apace this weekend between leaders, foreign ministers and diplomats, with the expectation that there are many more days to come in this conflict between Israel and Iran.
There are currently two so-called “crisis centres” running in the Foreign Office, both stood up in the last 48 hours.
One is handling the situation in the Middle East, the other the plane crash in Ahmedabad in India on Thursday.
The British government’s public response is very carefully calibrated.
In an interview the prime minister has done with Bloomberg and in the read outs of the conversations Sir Keir Starmer has had with fellow leaders, there is no explicit endorsement of Israel’s actions.
But there is a repeated acknowledgement of what are described as the UK’s “long held grave concerns” about Iran’s nuclear programme – the very thing Israel is attempting to destroy.
Whitehall officials say they had anticipated the prospect of Israel striking Iran.
We were told that UK preparations for potential Israeli strikes on Iran began in April last year.
On Monday, there was what was described as a “table top exercise” chaired by the Foreign Secretary David Lammy, where the nature and steps of the UK’s response was discussed.
“We were hugely conscious of the risk of this happening at some point,” one source said.
“But we are not getting into an assessment of the rights and wrongs of it,” said another source.
The prime minister’s conversation with the Israeli Prime Minister Benjamin Netanyahu happened at Mr Netanyahu’s request, we are told, and lasted around 15 minutes.
There was a conversation of similar length between Sir Keir and President Trump where, beyond birthday greetings (Donald Trump is 79 on Saturday and it is the King’s Official Birthday too), the only topic discussed was Israel and Iran.
The foreign secretary is expected to have calls with further counterparts in the Middle East on Saturday, after he held talks with representatives from Iran, Jordan and Saudi Arabia on Friday.
Mr Lammy also had a joint meeting with the foreign ministers of France, Germany and Italy, as well as the EU’s foreign affairs chief Kaja Kallas.
No ministerial-level Cobra meeting is expected today, but officials from multiple government departments will be meeting to discuss the latest throughout the day.
It’s understood that French officials informed the UK government last night that the upcoming UN summit on a two-state solution had been postponed.
The prime minister will fly to Ottawa in Canada later for talks with the Canadian Prime Minister Mark Carney expected to focus on security and trade.
Leaders of the G7 group of countries will gather in the Canadian province of Alberta on Sunday for their annual summit, with the situation in the Middle East at the top of their agenda.
