I would think American acceptance of civilian casualties would be contingent on agreeing that the war was justified, and I'll remind you the survey data we are talking about is specifically in reference to terrorism.

To grab a specific example from that page:

> almost one in four British Muslims believe that the 7/7 attacks on London were justified

Which you can read about here if you're not familiar: https://en.wikipedia.org/wiki/7_July_2005_London_bombings

> On the morning of Thursday, 7 July 2005, four Islamist extremists separately detonated three bombs in quick succession aboard London Underground trains across the city and, later, a fourth on a double-decker bus in Tavistock Square. Fifty-two civilians were killed and over 700 more were injured in the attacks, the United Kingdom's worst terrorist incident since the 1988 Lockerbie bombing as well as the country's first ever Islamist suicide attack.

Your counterargument that American's feel similarly to unintended casualties in war when targeting enemy combatants is very very weak. Who were the enemy combatants on the three subway trains? Who were the enemy combatants on the double-decker bus?

To put that another way: a large portion of muslims seeing terrorists in the same light that Americans see the US Armed forces means they approve of terrorists.