Without downplaying their influence and ability to meddle in our politics, Israel is in the end an outpost of the U.S. empire. There's certainly nothing in our own record to demonstrate a strong moral objection to maiming children.
You may be right. But if I surveyed any college campus today, I would expect indignation at the way we behaved in Vietnam and Iraq amongst 90%+ of those surveyed. A moral objection exists (perhaps not amongst the leadership of days of yore, but certainly in the younger generation). I would argue that moral objection is driving that discomfort in those familiar with this particular conflict