Prime Minister Benjamin Netanyahu said on Twitter that the Iranian fighters were targeting Israelis living in the Golan Heights, a region that Israel annexed from Syria after the 1967 Arab-Israeli War.
Yossi Mekelberg, a professor of international relations at Regent’s University, London, said there was a risk Israel would overstep and trigger a retaliation from its neighbors.
“If you infringe on their sovereignty — how much are they going to tolerate it?" he said. "We’re talking fine margins here and both sides can miscalculate.”
On Sunday, Lebanon's Iran-backed militant group Hezbollah accused Israel of hitting its media center in southern Beirut, and an Iraqi Shiite paramilitary group said Israeli drones had struck one of its positions near the Syrian border, killing one fighter and seriously injuring another. Hours later, Lebanese state media reported that Israeli drones had targeted the base of a Palestinian faction in eastern Lebanon.
Israel Defense Forces (IDF) declined to comment on the strikes in Lebanon and Iraq but did say it was responsible for the attack in Syria.
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“Israeli attacks on Syria, Iraq and Lebanon in the same period," said Nikolaos van Dam, a former Dutch ambassador to Iraq and special envoy for Syria. "It doesn’t look like a state being threatened, but rather like an Israeli threat and intimidation against its main adversaries in the region, including Iran.”
Iran’s network of proxies across the Middle East include thousands of Shiite fighters in Syria who have shored up the regime of Bashar al-Assad. Iran also backs Hezbollah, which currently dominates Lebanese politics. Israel shares a border with Lebanon to the north and with Syria to the northeast.
"The regional instability is a result of Iran's expeditionary or imperialist attempts," IDF spokesman Lt. Col. Jonathan Cornicus told NBC News on Monday. "We're not close to their border, they're close to ours."
Israel's northern border has caused the most concern.
Lebanese President Michel Aoun said Monday that his country had a right to defend itself and likened the drone strikes to a "declaration of war," according to Reuters. Hezbollah leader Hassan Nasrallah also threatened to retaliate.
Tensions between Israel and Hezbollah are at their highest since January 2015 when two Israeli soldiers and a Spanish U.N. peacekeeper were killed in fighting on the Lebanon-Israeli border, according to Assaf Orion, a senior research fellow at The Institute for National Security Studies in Tel Aviv.
“If a Hezbollah attack brings mass casualties, it is a slippery and steep slope,” he wrote in an email. “If there are no casualties, perhaps it will be easier for the parties to avoid their worst scenario of a destructive, devastating war of an unprecedented scale.”
The recent spate of strikes also come weeks before a national election in which Netanyahu seeks to present himself as the defender of Israel.
“Against political competitors blaming the prime minister for being ‘weak,’ the North and Iraq are where he can show power and resolve,” he said, referring to the alleged strikes in Iraq and Lebanon and the confirmed attack in Syria.
Netanyahu’s opponents have slammed him for refusing to strike harder at the Islamic militant group Hamas, which runs the Gaza Strip, after recent rocket fire from the blockaded Palestinian enclave. And Israel has previously hailed Trump's decision to withdraw from the 2015 nuclear deal and reimpose sanctions on Iran.
Mekelberg, of Regent's University, warned that Israel could get a response from its neighbors, regardless of the reasons for the raft of strikes.
"They've become overconfident that they can do it without facing retaliation, but there is no guarantee it won't happen this time and that it will not be painful," he said.
Lawahez Jabari reported from Jerusalem, and Linda Givetash and Saphora Smith from London.
Saphora Smith is a London-based reporter for NBC News Digital.
Linda Givetash is a London-based freelance journalist.
Lawahez Jabari is a producer based in Tel Aviv. She has covered the Middle East conflict — on both the Israeli and Palestinian sides — for more than a decade.
Charlene Gubash, Associated Press and Reuters contributed.