Maybe they need to change their flag
To save you the effort of translating it means "God is the Greatest, Death to America, Death to Israel, Curse on the Jews, Victory to Islam".
Clearly, as you say, they have no interest in killing Americans, Israelis or Jews in general.
And how exactly do you expect them to fight the US and Israel? How do they pose an existential threat to the UK? When have they targeted the US or Israel? They possess neither the means nor the will to engage in wars beyond their borders. The Iranians say the same kind of stuff and yet they haven't invaded another country for over 250 years. In fact, this is the exact slogan of the Iranian revolution. Need I also remind you that they are actually being slaughtered with US weaponry and with the blessing and support of the United States. But then again, you are another that just rejoices at the deaths of Arabs so I'm not at all surprised that you're supportive.