The war in Syria is a ruthless representation of regional changes that have taken place in the Middle East in recent years. At stake is a lot more than the future of Syria. The struggle for Syria is essentially about supremacy in the Arab East, the Mashreq (as opposed to the Arab West, the Maghreb of North Africa). The fact that Russia and Iran have become key players in this contest is a dramatic and revealing sign of the times, indicative of both Arab state weakness and American retreat.

Israelis have a special relationship with the Syrian civil war. This bloodbath is taking place along Israel’s northern border. Israel’s major population centers are a short drive from the conflict. They are an even shorter missile flight from it. So Israelis tend to watch the Syrian carnage not merely with the shocked horror of the rest of the world but also with the fearful question: What does this mean for Israel and its security, in the short and the long term?

Five major regional trends have come to a head in the Syrian civil war:

the decline of the Arab states, and even the disintegration of a number of them, including Syria, most dramatically; the consequent rise to the fore in the Middle East of the region’s non-Arab states—Turkey, Iran and Israel; the simultaneous rise of non-state actors, which have proliferated and evolved into critical forces: Hizballah, Hamas, Daesh (ISIS), Jabhat al-Nusra.; the decided and unprecedented shift in the historical balance of power between Sunnis and Shi’is in favor of the Shi’is; and the backgrounding of the United States in recent years has allowed the Russians the opportunity to return to the Middle East, in a manner impressively reminiscent of the leapfrogging by the Soviets over the “Northern Tier” into Egypt, at the height of the Cold war in the mid-1950s.

The overthrow of Saddam Hussein in Iraq and the country’s subsequent “de-Ba’thification” by the US invasion of 2003, removed the Sunni gatekeeper of the Arab East, empowered the Shi’ite majority in Iraq and transformed the country into a link in Iranian regional hegemonic design. Beyond Iraq, Syria provides the logistical lifeline between Iran and Hizballah in Lebanon. This has allowed for the maintenance of the organization and its military might, poised on Israel’s northern border as an essential component of Iranian deterrence.

For Iran, therefore, the Syrian theater is absolutely crucial, spoken of by some Iranians as that country’s “Stalingrad.” Even when cash-strapped and under sanctions, Iran poured many billions of dollars into the preservation of the Alawi regime in Syria. The Alawis, a breakaway sect from Shi’a, were an integral part of the “Shi’ite Crescent” stretching from Iran in the east, through Shi’ite dominated Iraq, to the Alawi regime in Damascus and finally to the Shi’ite militia of Hizballah in Lebanon. A defeat for Iran in Syria would be an extremely severe strategic setback that the Iranians and Hizballah could hardly afford. It would unquestionably tip the balance of power in favor of the Sunnis and against the Shi’is, as opposed to the trends of the last decade. Conversely a victory for Assad and his Iranian allies would be an important boost for their regional stature and for their capacity to pose a serious military threat to Israel. The Iranians sent some three thousand of their own men to fight in Syria; about 5,000 men from Hizballah are deployed in Syria too, as are Shi’ite fighters from Iraq and even Afghanistan—all fighting on Assad’s behalf.

As the civil war has dragged on in Syria, Israelis were initially not sure of the desirable outcome from their point of view. The notion of Syria, especially its border zone with Israel, being converted into a staging ground for the likes of Daesh, Jabhat al-Nusra and their ilk was hardly appealing. The Assads, father and son alike, had kept the peace with Israel for 40 years. So why should Israelis opt for the removal of the devil they knew? But eventually, the Israelis came to the conclusion that the preservation of the Assad regime, as a strategic asset for Iran and Hizballah, was the greater evil. These two were a far more dangerous combination than the motley array of Sunni militias roaming the killing fields of Syria.

In the early summer of 2015, the Assad regime appeared to be crumbling. Assad and his Shi’ite allies—Iran, Hizballah and the other Shi’ite fighters—fought desperately to avert defeat, facing what seemed to be insurmountable obstacles. But then, in late September, salvation arrived in the form of Russian intervention. The Russians tipped the scales in favor of Assad and his Shi’ite allies and changed the course of the war. They used their air force ruthlessly against rebels of various stripes to great effect, with little care for civilian casualties. The Russians also occasionally provided support for the regime and its allies with missiles fired from submarines in the Mediterranean and warships in the Caspian Sea.

And then, in a move as surprising as the decision to enter the fray in Syria, the Russians abruptly declared their intention to withdraw most of their forces from Syria.

It is not entirely clear what motivated the recent Russian decision, but it was probably influenced in no small measure by the serious contraction of the Russian economy and considerable cuts in defense spending, as well as a desire to have the West reduce sanctions over Ukraine. The Russian withdrawal may very well tip the scales in Syria yet again, this time against Assad, Iran and their allies.

When the cease-fire came into effect at the end of February, the Russians, their Iranian allies, and Hizballah (with Assad as their dependent) were firmly in the saddle. Having fought ruthlessly and with great determination, they had the upper hand, while the supporters of the very disparate Sunni opposition, the Saudis, the Turks and the US, had done a lot more talking than shooting.

Moreover, beyond Syria and “the Shi’ite crescent,” Iran also demonstrated considerable self-assurance. Sanctions relief allowed for large weapons’ deals between Iran and the Russians, including trade in sophisticated anti-aircraft missile systems and fighter aircraft. The Iranians have shown no signs of restraint in their regional ambition since the signing of their nuclear accord with the US and the other five powers in June 2015. To the contrary. While the accord put a brake on Iran’s nuclear project, the Iranians have continued to rail against the US, the Saudis and Israel. They treat the US with contempt, as shown by the public humiliation of the American servicemen who sailed inadvertently into Iranian waters in January. They continue to meddle in Yemen, and more recently, they defied the US and the international community with a much publicized ballistic missile test, in contravention of Iran’s international obligations.

Iranian achievements, self-confidence, and hegemonic designs were all matters of concern to Israel, as were some of the consequences of Hizballah’s participation in the Syrian war. On the one hand, Hizballah’s preoccupation with Syria, involving about a quarter of its regular forces, has made the organization far less likely to attack Israel. Hizballah has lost many men in Syria, apparently well over one thousand, but it has also gained very valuable military experience. It has evolved into much more of a real army than just a militia. Hizballah has some 45,000 men, of whom 21,000 constitute its regular forces. It also has more than 100,000 rockets and missiles trained on Israel. Any future confrontation with Israel will be more vicious and costly to both sides than the previous ones.

The Russian decision to withdraw would seem to undercut the position of the Assad regime, Iran and Hizballah. It appears to be designed to prod Assad and his allies to seek a peaceful resolution of the Syrian conflict, by making it clear to them that the Russians do not intend to fight on their behalf with no endgame in sight. The decision may embolden the Sunni opposition in Syria and beyond and represent a setback for Iran and the Shi’ite alliance that benefited so impressively from the Russian intervention. If this assessment turns out to be right, it would be a welcome relief for both Israel and the Sunni camp.

During Russia’s intervention, the Israelis made a concerted effort to coordinate with the Russians at the highest level. Prime Minister Netanyahu and President Putin have conferred frequently, as have senior military officers from both sides. A “deconfliction” regime was effectively established, and Israel clarified its key security interests in Syria to the Russians. The Israelis stressed their firm opposition to the transfer of sophisticated “game changing” weapons through Syria to Hizballah and their rejection of any form of deployment by Iran and Hizballah in the border area with Israel along the Golan. Such a deployment would turn the entire region from southern Lebanon across southern Syria into a Hizballah-controlled zone of potential conflict with Israel. It does seem that Israel did, in fact, reach an understanding with the Russians to show consideration for Israeli interests and to restrain Iran and Hizballah in this regard.

What will remain of that understanding when and if the Russians withdraw completely? It’s an open question.

Both Israel and Jordan would prefer that southern Syria be taken over by some form of dependable Sunni force that would keep the peace in the border zone. Just as the Israelis have taken military action to prevent the transfer of weapons systems to Hizballah, they have also conducted occasional military operations to prevent the Iranians or Hizballah from establishing any presence in the border zone with Israel. In addition, the Israelis have provided regular humanitarian aid to villages in the border zone and they have arrived at informal arrangements with various non-ISIS Sunni rebel militias in this area, all geared towards keeping the peace along the border, thus far successfully.

While the Russians have decided to withdraw the bulk of their forces, they will still remain in their air and naval bases in Syria and will, therefore, maintain their important strategic presence in the Eastern Mediterranean. Israel has every reason to promote good relations with Russia (needless to say, in coordination with the US). One of the reasons for the delay in Israeli-Turkish reconciliation is Israeli consideration for Russian opposition. Relations between Russia and Turkey, have deteriorated especially after the downing of a Russian fighter aircraft by the Turks last November.

On the other hand, at the end of January 2016, Israel entered into a strategic agreement with Greece and Cyprus, both of whom are very close to Russia. As the Arab world around Israel wallows in chaos and unpredictability and Iran makes regional gain at the Arabs’ expense it would seem only natural for Israel to seek the partnership of the other non-Arab players of the Eastern Mediterranean. This might include Turkey at some later stage, but in the meantime, both the Turks and the Israelis are unwilling to finalize a real rapprochement.

The Russians, it would seem, have become the ultimate arbiters of the Syrian civil war, leaving the US far behind. At the end of the day, the key historical question in the struggle for Syria is whether the country will remain part of the “Shi’ite Crescent,” return to the Sunni Arab fold, or become a loose federation that will be a little of both. At present, the Russians seem to be pushing for the federative compromise, with or without Assad. The Israelis have no choice but to wait and see, and to hope for the best.