Garvan Walshe is a former National and International Security Policy Adviser to the Conservative Party.

“We won’t allow a massacre of Syrian refugees.” Words, not from an American president, or a collection of European prime ministers, but from someone equipped with the means and the will to do something about it: Gabi Eizenkot, Chief of Staff of the Israel Defence Forces.

For four years, since the uprising against Bashar Assad began, Israel has kept to its policy of overt non-interference in the Syrian civil war. This is a quagmire into which it does not want to be drawn, though its studied indifference has from time to time been punctuated by implausibly-denied attacks on missiles, Hizbullah operatives and an Iranian general.

The sudden change has to do with just who the Sunni Islamist rebels of the Jabat al-Nusra are threatening. This al-Qaeda affiliate, now backed by Gulf money, is bearing down on the Druze, whom they consider heretics meriting the traditional punishment.

The Druze, whose religion is a form of heterodox Shi’ism, have survived as a minority in their combustible region by sticking resolutely to a feudal bargain. They offer unswerving loyalty to the powers that be – provided those powers are capable of protecting them. Israeli Druze, who number some 130,000, have served with great distinction in Israel’s army and police; some hold Knesset seats for the right-wing Likud and Yisrael-Beitenu parties. Though not Jewish, they have in the main found themselves a comfortable place in Israeli society. Druze of Syrian citizenship also live on the Golan Heights, on both sides of the border; they intermarry across it. In Syria, they have so far stuck with the regime, but now the regime has begun to lose the ability to stick with them in return.

To be sure, part of the impulse behind General Eizenkot’s warning came from loyalty to the Druze within Israel. But Assad’s weakness has left the Kirya, as the Israeli military headquarters is known, with a strategic dilemma.

Though the Assads were Israel’s enemies, by the 1990s they had become predictable, deterrable foes. Over the decades, Israel and Syria had developed an orderly if hostile relationship. When Israel destroyed Syria’s nuclear programme in 2007, no retaliation was forthcoming. Damascus may have hosted Khaled Meshaal (the head of Hamas) and been friendly to Hizbullah, but its economy was far too weak to allow Syria to pose a serious symmetric threat.

The civil war changed this irrevocably. Hizbullah and Iran immediately become more important as the regime began to depend on them for its survival. Iranian officials are now deeply entwined into the Syrian security apparatus, while Hizbullah fighters have been dying in droves. Meanwhile, the regime’s moderate enemies have been killed, sidelined or radicalised. Neither of the most powerful remaining factions: the Jabat al-Nusra and ISIS, can be deemed “good for the Jews.” Israel would probably be able to come to a modus vivendi with either, but only after inflicting military defeat upon them, perhaps more than once.

A unified Syria under ISIS or other radical Islamist control is not, however, in prospect. Kurdish rebels are interested in consolidating power over the areas in which Kurds live. ISIS will grab land where it can, supremely indifferent to the region’s post-Ottoman frontiers. Whatever the formal “dignified” borders may be, the “efficient” transmission of power is quite different.

In recent months, the regime’s authority has weakened considerably. This week, the Syrian government, no longer able to recruit Druze and Christian villagers, accepted that they could fulfil their duties of military service by “enlisting” to defend their own villages. This matters: those men will no longer take instructions from Damascus, but they also know they are too weak to survive without a protector (as Sunni tribesmen in Iraq, who have had to acquiesce in ISIS’s rule, know all to well).

They may wonder whether a concentrated Druze power, underwritten by Israeli deterrence, stands a chance of protecting that population from Sunni extremists. The prospect suggests a new military understanding: Israeli deterrence can prevent the Islamist rebels from bringing heavy weaponry to bear, while a Druze population can prevent them holding territory.

Until now, the Druze have been loyal to the regime but, as the regime’s ability to protect them continues further, the Druze’s search for a new protector could see Israel drawn further into Syria’s civil war. Fraught though this would be, it might seem preferable to the alternative: Islamist fanatics consolidating control of the border on the Golan, threatening to massacre people with close ties to Israeli citizens.