[John Healey, Defence Minister in 2021] was told that a proposed military operation would need to be in accordance with UK law and the UK’s interpretation of relevant international law. The UK’s position on pre-emptive strikes is well known.
In the lead up to the Iraq war, the then attorney-general, Lord Goldsmith, argued that international law permitted force only in self-defence where there was an actual or imminent attack. Goldsmith argued only later that a UN resolution relating to Iraq made it a legal war.
In Trump’s statement on Wednesday night, the president made an explicit reference to Iran and the role that the UK might play in any attack. He also appeared to suggest that UK support would be legal under international law, as Iran could potentially strike the UK.
“Should Iran decide not to make a Deal, it may be necessary for the United States to use Diego Garcia, and the Airfield located in Fairford, in order to eradicate a potential attack by a highly unstable and dangerous Regime” he wrote on his Truth Social site.
“An attack that would potentially be made on the United Kingdom, as well as other friendly countries.”