Israel held out the prospect on Tuesday of eventual contacts with Syria under President Bashar al-Assad, in a nod to his regime-consolidating advances in a seven-year-old civil war that Israeli officials had initially predicted would topple him.
Assad's Russia-backed forces have advanced in southwest Syria and are on course to reach Quneitra, a rebel-held district abutting the Golan Heights frontier with Israel. That has stirred Israeli concern that he may try to deploy troops there in defiance of a 1974 UN demilitarisation accord on the Golan.
Touring the Israeli-occupied Golan, Defence Minister Avigdor Lieberman ramped up threats to use armed force should Damascus encroach militarily. "Any Syrian soldier who will be in the buffer zone risks his life," Lieberman told reporters.
However, Lieberman appeared to signal acknowledgment that Assad would regain control of the Syrian side of the Golan.
Asked by a reporter if he anticipated a time when Quneitra crossing would be reopened under the UN-monitored armistice between Israel and Syria, and whether the two old enemies could establish "some kind of relationship", Lieberman said: "I reckon we are a long way from that, but we are not ruling out anything."
His remarks could foreshadow a more open approach to Assad ahead of Israeli Prime Minister Benjamin Netanyahu's Syria talks with Russian President Vladimir Putin in Moscow on Wednesday.
Under Assad family rule, Syria held direct negotiations with Israel in the United States in 2000 and indirect talks mediated by Turkey in 2008, discussions predicated on the return of all or part of Golan areas that Israel seized in a 1967 war.
No agreements were signed, and after the Syrian civil war erupted in 2011, Israeli officials – including former Defence Minister Ehud Barak – said Assad could fall within weeks. The tide turned in Assad's favour in 2015 when Russia intervened militarily on his behalf. Iran and Lebanon's Hezbollah have also sent reinforcements to Syria.
While formally neutral on the civil war, Israel has carried out scores of air strikes on suspected Iranian or Hezbollah deployments and arms transfers in Syria, seeing these as a greater threat than Assad and warning him not to abet them.
"This effort to set up a terrorist infrastructure under (Syrian) regime auspices is unacceptable, as far as we are concerned, and we will take action with great might against any terrorist infrastructure that we see and identify here in this area," Lieberman said during his Golan tour.