“Terrorism, in its broadest sense, is the use of violence against non-combatants to achieve political or ideological aims.”

If you call this terrorism, you can call anything terrorism, and anybody can be a terrorist. If you’re willing to do that to aid the Israel fascist state, that makes you a fascist.

And sure, that was very much illegal and they could have used any number of laws applicable to attacking a military base. Just not terrorism. But the UK military is involved in a partnership in the gaza war. They are not “non-combatants”