A Syrian fighter jet shot down after breaching the nation's airspace could have flown anywhere over Israel within five minutes given its speed and the country's small dimensions, Israeli military sources said Tuesday.
The jet, believed to be a Sukhoi 24, entered Israeli airspace Tuesday morning after taking off from an army air base in eastern Syria and was struck by a surface-to-air Patriot missile in what was described as Israel's first engagement with a Syrian fighter plane in three decades, according to the Israeli military.
According to media reports, the two pilots ejected safely, landing in Syrian territory, and the downed jet fell inside Syria as well.
Three weeks ago, Israeli air-defense systems shot down a drone over the same area. In both cases, it wasn't immediately clear if the aircraft intended to target Israel but was believed to be spillover from the civil war in Syria.
An Israeli military source said the plane shot down Tuesday probably intended to strike rebel strongholds in southern Syria -- but it crossed 800 meters into Israeli airspace before turning back toward Syria, after the decision to intercept it had already been made.
Defense Minister Moshe Yaalon said the plane approached Israeli territory in a threatening manner and crossed the border. "We will not allow anyone to violate our sovereignty and will react aggressively to any such attempt, whether deliberate or accidental," he told Israeli media.
Ram Shmueli, former head of Israel's air-force intelligence, said the country's small size leaves "no room for mistakes" in defending its narrow airspace. "We have to be alert 24/7 for drones, jets and even civilian aircraft."
Shmueli dismissed any connection between the interception and the U.S. strike against Islamic State targets in Syria overnight. "We are not part of the coalition, even though we support the idea," he said, adding Israel was just defending its border.
Aviation security authorities have issued an open-ended instruction to all civilian aircraft, including drones and crop-dusters, to keep a 10-kilometer (6.2-mile) distance from the Israel-Syria border.
Increasingly, the civil war in Syria has inched closer to Israel, with rebel forces wresting control of part of the strategic Golan plateau from Syrian President Bashar Assad's army. Fighting has shut down the only formal crossing between Israel and Syria at Quneitra and driven out the United Nations peacekeeping force that has overseen the disengagement between the two countries' armies since 1974, effectively mooting its mandate.
Throughout the warfare in Syria that began in 2011, Israel has been careful to stress that it is not a party in Syria's internal battle, while at the same time monitoring developments closely and responding to any incidents of cross-border fire. Israel has reinforced troops in the area, upgraded the border fence and kept close watch on the fast-shifting events to its north.
Israel has welcomed the U.S.-led coalition against Islamic State extremists in Iraq and Syria and is reportedly sharing intelligence with Western allies.
Israel is believed to have carried out several airstrikes against targets inside Syria during the Syrian conflict, though Israeli authorities have generally not acknowledged the attacks publicly. U.S. officials have said the Israeli strikes were generally aimed at weapons stockpiles destined for Hezbollah, the Lebanese group that is an ally of the Syrian government and an enemy of Israel.
In June, Israel acknowledged an attack with warplanes on targets in Syria after a shell from Syrian territory struck a vehicle in the Israeli-occupied section of the Golan Heights, killing an Israeli and wounding two others.