The loss of an Israeli jet to Syrian fire over the weekend has raised the risk of a more forceful response from Israel to deter Iranian military expansion across its border, which could open up another front line in war-torn Syria.
The clash began on Saturday morning after Israel said it intercepted an Iranian drone that had infiltrated its airspace from Syria. Israel responded that day with airstrikes on Syrian military positions, and Syria shot down one of the Israeli warplanes, which crashed in Israeli territory.
Israel then carried out more-extensive airstrikes Saturday deep inside Syria targeting what its military said were Syrian and Iranian military positions.
Israel’s pilots ejected from the aircraft as it crashed in Israeli territory, with one taken to a hospital in serious condition. Pro-regime Syrian media reported that about 25 people died in the Israeli strikes.
This is the first time in more than 30 years that Israel has lost a fighter aircraft, and its strong reaction illustrates how the competing aims of Iran and Israel could lead to a war between the two Mideast powers—as Tehran increases its military presence in Syria in a move Israel has warned it won’t allow.
“We will continue to strike at every attempt to strike at us,” Israeli Prime Minister Benjamin Netanyahu said Sunday at his weekly cabinet meeting, according to a statement released by his office.
A spokesperson for the Syrian regime couldn’t immediately be reached for comment on Saturday’s incident. Syrian state media called the strikes a “new Israeli aggression.”
Read Related Coverage
The White House on Sunday called on “Iran and its allies to cease provocative actions,” saying it supports Israel’s right to defend itself from the Iranian-backed Syrian and militia forces in southern Syria.
Israel for years has largely stayed neutral in the Syrian civil war, only launching airstrikes against weapons convoys bound from Iran to Lebanese group Hezbollah. But it increasingly has hit military sites in recent months, fearful of an Iranian presence on its border.
Backed by Russia, Iran and Hezbollah, Syrian President Bashar al-Assad is emerging victorious in his country’s civil war and has become bolder in countering Israeli breaches of airspace by launching antiaircraft missiles.
Iran says Syria has the right to defend itself. It denies trying to set up military bases in Syria but also has said it would remain in the country as long as Mr. Assad requires an Iranian presence.
Israel’s attempts to stop Iran and Hezbollah setting up on its northern border are likely to lead to further confrontation, defense experts say, as neither side appears willing to back away from their goals.
“There is a determination by Iran to build a military force in Syria and Lebanon and there is determination by Israel not to let it happen,” Amos Yadlin, director of the Tel Aviv-based Institute for National Security Studies and a former air force general told reporters on a call late Saturday organized by nonprofit The Israel Project. “And the two vectors are colliding.”
Defense experts said Israel launching what it described as a large-scale attack on Syrian and Iranian military sites in retaliation for the downing of its aircraft was meant to demonstrate the power of its air assets and intelligence capabilities, and warn off the Iranian-backed forces from further conflict.
In response to the Israeli strikes, Hezbollah said the confrontation would mark the beginning of a new strategic phase against Israel, although it didn’t take any specific military action.
Israel and Hezbollah have traded barbs in recent months, as Israeli officials have accused Iran of building precision weapons factories in both Lebanon and Syria for Hezbollah and claim the group effectively controls the Lebanese government. Hezbollah and the Lebanese government deny the Israeli claims.
Although Israel and Russia have put in place a deconfliction mechanism to ensure their jets don’t collide over Syrian skies, Moscow appeared to criticise Israel’s actions on Saturday, saying it was “absolutely unacceptable” to threaten Russian troops on the ground.
Mr. Netanyahu visited Moscow last month to meet with President Vladimir Putin and communicate that Israel wouldn’t allow Iran to set up permanently in Syria.
Israeli officials have said Russia wants to find a peaceful solution to the Syrian war and so doesn’t want to see a confrontation between Israel and Iran, but Moscow hasn’t publicly warned Tehran off establishing military bases in Syria.
In a bid to prevent Iran and Hezbollah setting up on the Syria side of the Israeli-controlled Golan Heights, Israel in recent years has supported the Sunni rebels there with money and humanitarian aid with the view of creating a buffer zone of friendly forces. But Israeli officials don’t believe that the fighters there would play a major part in any future conflict.
—Sune Engel Rasmussen contributed to this article.
Write to Rory Jones at email@example.com