JERUSALEM (Reuters) - Israeli leaders welcomed the U.S. airstrikes in Syria, saying they sent a strong message that the Trump administration would not accept the use of chemical weapons and was a warning to other hostile states, including Iran and North Korea. Prime Minister Benjamin Netanyahu said Israel stood fully behind the decision to fire more than 50 Cruise missiles at the airfield from where Washington said President Bashar al-Assad’s forces launched a deadly chemical attack this week. “In both word and action, President Trump sent a strong and clear message today that the use and spread of chemical weapons will not be tolerated,” Netanyahu said in a statement.  “Israel ... hopes that this message of resolve in the face of the Assad regime’s horrific actions will resonate not only in Damascus, but in Tehran, Pyongyang and elsewhere.” During the six-year conflict in Syria, Israel has largely stayed on the sidelines, carrying out only occasional airstrikes when it feels threatened, including by the movement of weapons to Lebanese Hezbollah militants on its frontier with Syria. Israeli officials said the United States had informed them about the airstrikes ahead of time, but it was not clear whether Israel provided intelligence or any other form of input to the White House to support carrying out the attack. Israeli Defence Minister Avigdor Lieberman called the U.S. move an “important, necessary and moral message”. “The American notification to the Israeli military and defence establishment before the strike is additional proof of the strength of the deep ties,” he said.  Yaakov Amidror, Israel’s former national security adviser, said the calibrated response by the United States had sent a message that Washington was reengaged in the region and that Russia did not have free rein in Syria.  “The Americans are telling the Russians: ‘You are not alone any more, not in Syria not in the Middle East, and we are ready to take all the steps to be involved, and if you neutralise the U.N. Security Council, we will know how to act without its permission’,” he said on a conference call with reporters.  “Yet again, military action is an option that will be used when the Americans decide that it should be used and (tell hostile states): ‘Watch your behaviour and your attitude towards American interests’.” Asked about the risk of retaliation, he said: “The chances for an attack initiated by either Syria or Hezbollah is even less today than before because now it is understood that if they violate the interests of the United States of America ... this administration is ready to take action.” As for Israel stepping up its actions in Syria, Amidror said it would only engage if either of its two red lines are crossed: if strategic weapons are passed to Hezbollah units or if launch sites for attacks are set up in the Golan Heights, where Israeli-occupied territory borders Syria. “We will stay on the sidelines because our strategic decision was not to take part in this war. If there is something specific that we can do militarily or from an intelligence point of view and so on, I’m sure that Israel would be more than happy to contribute to such efforts.”        