Prime Minister Benjamin Netanyahu warned Iran not to test Israel and compared Tehran to Nazi Germany on the day Israel commemorates the murder of 6 million Jews during the Holocaust.
"I have a message to the Iranian rulers: Do not test the determination of the state of Israel," Netanyahu said on April 11 at Yad Vashem Holocaust Memorial in Jerusalem. "These are not empty words.
"During the Holocaust, we were helpless, defenseless, and voiceless. In truth, our voice was not heard at all. Today, we have a strong country, a strong army, and our voice is heard among the nations," Netanyahu said.
The Israeli leader's speech came two days after an air strike on a Syrian military base that Syria and Iran blamed on Israel. The strike killed at least 14 pro-government fighters, including seven Iranian soldiers.
Netanyahu has repeatedly warned Iran against trying to establish a permanent military presence in Syria, where it has been President Bashar al-Assad's staunchest ally in a seven-year civil war against Sunni rebels.
After the air strike, Tehran warned that it would retaliate against Israel, prompting Tel Aviv to put its military forces on high alert.
Israel appeared to justify the air strike afterward by citing an alleged chemical-weapons strike by Syrian forces in the town of Douma over the weekend that killed at least 40 Syrian civilians.
The United States and European allies are currently threatening to carry out retaliatory air strikes over the incident.
Netanyahu said in his address that every generation must "confront evil and aggression."
"We saw the Syrian children being slaughtered with chemical weapons. Our hearts were torn from the horror," he said.
"Today...a murderous regime threatens us.... This regime explicitly declares that it intends to annihilate us, the Jewish state," Netanyahu said.
He said a big lesson of the Holocaust is that "murderous evil" that goes unchallenged "spreads quickly and gradually threatens all of humanity."
Israel considers Iran an archenemy because of Tehran's repeated calls for destruction of the Jewish state and support for violent anti-Israeli groups like Palestine's Hamas and Lebanon's Hizballah.
Netanyahu compared Iran's 2015 nuclear deal with world powers to the 1938 Munich Agreement, which was seen as a failed attempt by European powers to appease Nazi Germany.
The Iranian nuclear deal lifted sanctions on the country in exchange for limits on Tehran's nuclear activities. Iran insists its nuclear program is for peaceful purposes, such as power generation.
Also on April 11, Netanyahu in a phone call told Russian President Vladimir Putin that Israel "will not allow Iran to establish a military presence in Syria," his office said.
The Kremlin said the two leaders "discussed recent Israeli air strikes against the T-4 air base," and Putin called on Netanyahu not to take any action that could "further destabilize" Syria.
Putin "stressed the importance of respecting Syria's sovereignty," the Kremlin's website said.