BACK in 2011, when Bashar Assad started to slaughter Syrians protesting against his dictatorial rule, the neighbouring states of Turkey and Jordan were keen to stop the bloodshed. Mainly due to America’s reluctance to get embroiled in another messy Middle Eastern affair, neither acted. Four years later, both are once again giving serious consideration to wading into Syria.

Independently of one another, the countries’ officials are said to be planning to set up buffer zones along their borders just inside the war-torn country. Turkish papers talk of an area 110km long and 33km deep (70 miles by 20 miles) along Syria’s northern frontier. The Financial Times, citing anonymous officials, reports that Jordan plans to establish a haven across the provinces of Deraa and Suwayda in southern Syria. In the case of Jordan carefully vetted Syrian rebels, rather than foreign forces, would man the areas.

Such zones have been mooted many times before, but the urgency has risen as Syria continues to disintegrate. Several years ago the idea was to give the Syrian rebels an area in which to organise. Later on, as the war worsened and thousands of refugees fled, it was justified on humanitarian grounds. Today Syria’s neighbours are more interested in protecting themselves. “It’s a matter of national security,” says an adviser to Jordan’s king.

Turkey’s chief concern is that Syrian Kurds might carve out a state for themselves, which would become a magnet for Turkey’s own Kurds, who have at times called for self-rule within Turkey. Syrian Kurdish fighters linked to Turkey’s Kurdistan Workers’ Party (PKK) took over the town of Tal Abyad in mid-June with the help of rebel units and American bombers. As a result, three enclaves that they hold are now pretty much joined together. On June 26th Recep Tayyip Erdogan, Turkey’s president, vowed that he would “never allow the establishment of a Kurdish state in northern Syria”.

Although the Kurds accuse Mr Erdogan of tacitly supporting IS, the jihadists are also a growing worry for Turkey. They are too close for comfort in Jarablus, a border town that abuts the Turkish province of Kilis, and look poised to grab Azaz, a key supply route for other rebels supported by Turkey, Qatar and Saudi Arabia.

It was IS’s conquest in May of Palmyra, 240km from the Jordanian border, that startled the kingdom into intensifying what the king’s men call “precautionary measures”. Officials fear the jihadists will fill any vacuum left by the Assad regime, which has lost key southern bases and the Druze heartland of Suwayda in recent weeks. A buffer zone would help allied rebels hold them off, while putting Jordan’s northern towns out of reach of rockets, which last week rained down on Ramtha, killing one person. Syria’s neighbours would also like to see more Syrians stay inside their own country. Turkey is home to 1.8m Syrian refugees; uprooted Syrians are now a fifth of Jordan’s population.

The weakened Assad regime poses little threat to these plans. A buffer zone is easier to set up in the south than the north, where rebel groups are more fissiparous and devout. After months of vetting, the Southern Front, a conglomerate of over 50 rebel groups, is already receiving training, salaries and weapons from Jordan.

But there is scepticism that either country will do more than sabre-rattle. Analysts question their ability to control rebels from a distance. Turkey’s army is reluctant to get bogged down in a conflict that is likely to draw in Kurds and IS alike. And unlike previously declared buffer zones, such as that in northern Iraq after the 1991 Gulf war, the safe havens would not be protected by a UN-sanctioned no-fly zone.

America, the only power that could enforce such a restriction, does not want to get involved, creating the biggest obstacle to any buffer zone. Its relations with Turkey are acrimonious. Barack Obama recently complained that Turkey should be doing more to stop the flow of foreign fighters heading through its territory to join IS. The Americans are also irritated by Mr Erdogan’s refusal to let the coalition against IS use Incirlik airbase to carry out air strikes. (Turkey says the price is American agreement to a no-fly zone.)

The best model for what Jordan and Turkey could achieve may be Israel’s. It has quietly facilitated something akin to a buffer zone along its (shorter and UN-patrolled) frontier with Syria. It has fostered links with southern rebels. They recently kicked Mr Assad’s forces, reinforced by Hizbullah and Iranian Revolutionary Guards, out of the adjoining province of Quneitra. Today, Israel looks like the safest of all Syria’s neighbours.