Israel, along with many Western countries, believes Iran is pursuing nuclear weapons, and Netanyahu has repeatedly raised concerns that international pressure to curb the Iranian nuclear program has been insufficient.
"Assad's regime has become a full Iranian client and Syria has become Iran's testing ground," Netanyahu said. "Now the whole world is watching. Iran is watching and it wants to see what would be the reaction on the use of chemical weapons."
For this reason, many Israelis reacted with disappointment after Obama announced over the weekend that he would seek a congressional vote before a use of force against Assad. Israeli newspapers and commentators criticized the American leader for appearing weak and indecisive.
"You can't count on someone who isn't sure of himself," said Hanna Tzikli, a resident of northern Israel.
Israelis have expressed their desire for American action with a mixture of moral and strategic concerns. Watching civilians die from poisonous gas is painful in a country built on the ashes of the Holocaust, in which the Nazis sent countless Jewish victims to their deaths in gas chambers.
It has also sharpened concerns that Assad might one day use these weapons on Israel. Special gas-mask distribution centers have been flooded with nervous people in recent days seeking to get their protection kits.
"If he used chemical weapons against his own people, he'd have no problem using them against others," said Oded Eran, a senior researcher at the Institute for National Security Studies, a Tel Aviv think tank.
Still, the operating assumption appears to be that a U.S. strike would not necessarily precipitate a Syrian reprisal against Israel. With Assad believed to be gaining the upper hand in the war, Israeli decision makers suspect he would be careful not to weaken his military by opening up a new front against a strong rival.