Displaced Syrians from the Daraa province fleeing shelling by pro-government forces wait in a makeshift camp to cross the Jordanian border, near the town of Nasib, southern Syria, on July 1, 2018
CNN  — 

An agreement reached Friday may offer a glimmer of hope in a fast-deteriorating situation in southwestern Syria, where at least 330,000 people – half of them children – have fled their homes in the face of a fierce regime offensive.

It may also strengthen Russian President Vladimir Putin’s hand ahead of his summit with President Donald Trump on July 16, where both sides say Syria will be on the agenda.

Russian officials and Syrian rebel groups agreed on the truce in the province of Daraa, south of Damascus. Syrian troops will withdraw from some areas they have captured and allow rebels of the Free Syrian Army to take back control of four disputed towns.

A CNN team on the Jordanian-Syrian border Thursday witnessed intense bombing and artillery strikes against areas held by the rebels, with Iranian militia operating heavy artillery known as the “Elephant” because of the characteristic noise it makes on launch. The Syrian Observatory for Human Rights reported more than 600 airstrikes, including the use of barrel bombs, in Daraa province since Wednesday.

The truce is a tentative first step towards encouraging civilians to return home, but the area remains highly volatile and the agreement doesn’t cover large areas of the province.

Not only is a humanitarian disaster looming, but the fighting is concentrated in an area where the borders of Syria, Jordan and Israel meet. Add to that the fact that pro-Iranian militia are in the area, as well as a pocket of militants supporting ISIS and what you have is a cauldron of bad possibilities.

Russia’s role crucial

The Russians are crucial to any truce. Russian airstrikes helped the regime advance. And now Russian military police will deploy to Daraa to guarantee the ceasefire and ensure the rebels give up their heavy weaponry.

Many of the civilians stranded along the border with Jordan are frightened of retribution by the regime, which captured the main crossing at Naseeb on Friday. Jordanian authorities, citing security concerns, have refused to allow them to cross and have moved military reinforcements to the frontier. Jordan is already host to more than 600,000 registered Syrian refugees; and maybe double that number of Syrians altogether.

The International Rescue Committee said many of the stranded civilians “are struggling without enough shelter and water while contending with 45-degree heat, desert winds and scorpions.”

UNICEF spokeswoman Juliette Touma told CNN it’s the largest displacement of civilians in southern Syria since the war began, with 180,000 children forced from their homes in three weeks of fighting. Touma said civilians were dispersed over a wide area. It was too early to tell what sort of impact the truce might have, she said, but there was urgent need to get water and shelter for the displaced.

The CNN team reported that UN agencies had set up medical facilities at Naseeb, but the regime’s seizure of the crossing may deter some from trying to reach the area. Medical staff said children were developing chronic heat-related fevers and diarrohea. The IRC reported at least a dozen children had died at the border.

In the area close to the occupied Golan Heights, Israel has been delivering some aid across the border.

What has happened in Daraa mirrors other advances by the regime since the fall of Aleppo at the beginning of 2017. One-by-one, areas that were agreed as ‘de-escalation zones’ have come under attack by Assad’s army and pro-regime militia, backed by Russian airpower. Once rebel groups are weakened, the Russians step in to stabilize the area.

US response muted

The de-escalation zone in the southwest was agreed by Russia, Jordan and the US in June 2017. The Russian Foreign Ministry said this week that the offensive fulfilled an obligation to “eradicate terrorists.”

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The US response has been muted. The deputy ambassador to the UN, Jonathan Cohen, said last week that Washington was “deeply concerned” by the Syrian regime’s new offensive.

“Once again, Russia is justifying a military offensive by the Assad regime by saying that more than half the de-escalation zone is controlled by terrorists. That is just not true,” Cohen said.

The collapse of rebel resistance in southwestern Syria leaves only two significant areas beyond the regime’s (and therefore Russian) control.

One of those areas is held by the US-backed Syrian Democratic Forces, which hold just over one-fifth of Syrian territory in the north and east.

President Trump said in April he’d like to bring home US troops supporting the SDF very soon. The Institute for the Study of War in Washington expects President Putin to seek to tempt Trump into following through on that wish – and says the Russian-Iranian coalition “is building a network of deniable proxy forces to attack the US and its local partner – the Syrian Democratic Forces – in Eastern Syria.”

It’s been seven months since Putin ordered a partial withdrawal of Russian forces from Syria, saying “the Russian armed forces, together with the Syrian army, have defeated the most lethal group of international terrorists.”

However you describe the opposition to Assad, the campaign in Daraa has brought Putin’s goal another step closer.

CNN’s Jomana Karadsheh contributed to this report.