The cease-fire that took effect in Syria on Friday at midnight has held, barely, for two days now in most of the country. The fighting that still continues is mainly along the front lines against the Islamic State (ISIS), which isn’t party to the deal.

Nevertheless, the Russian air force Sunday bombed several towns north of Aleppo controlled by rebel groups that are party to the cease-fire. A top official with the Syrian opposition has blamed the government and its allies for cease-fire violations that killed more than two dozen people, warning it will be difficult to resume peace talks next month. Raid Hijab, who heads the High Negotiations Committee, an umbrella for opposition and rebel factions, said in a statement directed to UN chief Ban Ki-moon that Russian, Iranian and government forces have not stopped hostilities since the truce went into effect.

The Israeli defense establishment, meanwhile, remains skeptical about the cease-fire’s durability. In Israel’s view, the containment of hostilities in the last two days is due mainly to the exhaustion on both sides. After almost five years of bloody battles, all sides are using the cease-fire to regroup, give their fighters a much-needed breather and take deliveries of logistical and humanitarian aid for combatants and civilians alike.

But it’s doubtful that this mutual interest in a cease-fire will last for long, since the agreement has two glaring weaknesses. One is that some parties to the fighting aren’t included in the truce. The other is that it lacks any plan for shifting from a short-term truce to a long-term diplomatic agreement that could actually end the civil war, which has so far claimed almost half a million lives.

The cease-fire doesn’t include either ISIS or the Al-Qaida-linked Nusra Front. Since territory controlled by ISIS borders on territory controlled by government forces, other Sunni rebel groups and Kurdish militias, the ongoing fighting against this organization could easily spill over into these areas.

Even more importantly, the Nusra Front has ties with many of the other Sunni rebel groups, and in some areas it has formed a joint front against the Assad regime with some of these groups. Thus in places where Assad and his allies – primarily the Russian air force – are continuing to attack the Nusra Front, they are liable to hit other rebel groups as well, especially since the Russians aren’t overly careful about where they drop their bombs.

But even if the Russians surprise everyone by exercising restraint and the cease-fire confounds expectations by holding, it’s hard to see how this truce can be converted into a longer-term diplomatic agreement acceptable to all sides.

Early this month, the Assad regime not only managed to encircle Aleppo, in northern Syria, almost completely, but also racked up its first territorial gains in a long time in the country’s south. Forces loyal to Assad now control part of the town of Daraa, and the rebels have had to evacuate the nearby town of Sheikh Maskin and other, smaller towns, mainly due to heavy Russian bombing.

The regime’s advances in the south initially roused some concern in Israel that Assad would exploit his momentum to try to strengthen his hold over the Syrian side of the Golan Heights, along the border with Israel. That could disrupt the relative quiet that has prevailed along the border, which rests on unofficial understandings between Israel and the rebel militias that control most of the Syrian Golan.

To date, there hasn’t been a single attack on Israel from the Golan by the Sunni rebels, even though Nusra Front forces are present in parts of the Heights, while the corner where Syria, Israel and Jordan meet is controlled on the Syrian side by a group affiliated with ISIS, Shuhada al-Yarmouk. The main reason for this quiet is that residents of Syrian villages along the border want to continue receiving humanitarian aid from Israel, which sometimes includes medical treatment in Israeli hospitals.

The rebel militias currently control the entire border with Israel except for one enclave that includes the town of Quneitra, the Druze village of Khader and the Syrian side of Mount Hermon – an area about four kilometers wide.

Nevertheless, there is currently no sign that the regime plans a major offensive on the Syrian Golan. The government’s main concern in the south is retaining control of two major arteries – the Daraa-Damascus highway and the Quneitra-Damascus highway. Beyond that, it appears to have no intention of diverting forces to the Golan such that it needs to maintain its hold on Damascus and the cities to its north. Thus in the weeks preceding the cease-fire, only about 10 percent of Russian airstrikes were in southern Syria, while 90 percent targeted the area from Damascus northward.