The Israelis are protecting innocent citizens from rocket and other attacks out of Gaza. Protection of civilians is not a game, and anyone who interferes does so at his own risk. In the U.S., there is a legal defense called "assumption of risk." I cannot think of a more appropriate use of that defense then in this case. If you intentionally mess with the bull, don't wine and cry when you get the horns.
U.S., allies conduct 31 air strikes in Syria and Iraq against ISIS militants (Reuters)
from the article: Father of teen killed in Gaza flotilla raid seeks American justice