(Reuters) - Israel could pay a heavy price -- including damage to peace efforts with the Palestinians -- over the killing of 10 international activists on a Turkish ship trying to break a blockade of Gaza.
Foreign anger at the boarding of the pro-Palestinian flotilla was loud even among Israel's allies and may drown out its argument that such action was needed to keep Gaza's Hamas rulers isolated and peacemaking efforts afloat.
Islamist Hamas's rival for Palestinian loyalties, secular president Mahmoud Abbas, was quick to condemn the naval attack as a "massacre" -- an ill omen for the U.S.-mediated negotiations with Israel on which he embarked three weeks ago.
President Barack Obama will have to balance relations with Turkey and other Muslim allies of the United States against Washington's ties with Israel.
Israeli Prime Minister Benjamin Netanyahu, on a visit to Canada when the Israeli raid took place, canceled a planned White House meeting with Obama on Tuesday and would leave later on Monday for home, Israeli officials said.
