Robin Simcox, a research fellow at the Henry Jackson Society, says Yes
There is, correctly, a high threshold for the government to meet before carrying out a targeted strike against a British citizen.
This is the first time such a strike has taken place, and it was done to prevent Reyaad Khan – an Islamic State terrorist – from causing bloodshed here in the UK. The government had no choice.
The UK has no troops on the ground in Syria, so capturing Khan was impossible. He had shown no intention of returning to the UK, so he could not be arrested by the police.