For U.S. and Russia, War in Syria is Mainly in the Air

The United States and Russia, two former Cold War foes that have brokered a ceasefire deal for Syria, rely mostly on air raids in their separate military campaigns in the war-wracked country.

Here are key points about how these two powers are trying to fulfill their military objectives in Syria, where a bloody civil war has raged since 2011.

- Different military objectives -

The Russians are backing President Bashar Assad's regime, saying they are fighting "terrorist" groups. But Moscow stands accused of actually bombing rebel groups fighting Assad beyond the Islamic State group and the Fateh al-Sham Front -- previously named al-Nusra Front until it split with al-Qaida.

With Russia's support, Damascus has gained ground against the rebels in western Syria. Government forces have also made gains against IS forces, including in Palmyra.

U.S.-led coalition forces are meanwhile seeking to help local groups regain territory seized by IS fighters. Until now, these local forces have mostly been Syrian Kurdish militias and their Arab allies. 

These militias have retaken large chunks of land in northeastern Syria. Coalition warplanes also backed an offensive by Turkey and Arab groups in late August to regain territory along the Turkish-Syrian border.

- Russia's presence in Syria -

The Russian military, which has actively backed Assad's regime since September 2015, has a physical foothold in the country, including a naval installation in the western port city of Tartus and Hmeimim Air Base, which houses the S-400 advanced surface-to-air missile system.

Russian planes carry out air raids from Hmeimim, as well as from Russia. Moscow has also launched missile attacks from ships in the Caspian and Mediterranean Seas, via submarine and from planes taking off from Iran.

There are also Russian forces on the ground, including special forces.

In June, Russian lawmakers passed a measure that spoke of 25,000 Russian troops and civilians involved in Syria since Moscow's intervention began there.

About two dozen Russian soldiers have been killed in Syria.

- U.S. launches attacks from outside Syria -

The United States launches some of its attacks from Incirlik Air Base in neighboring Turkey, where it has stationed A-10 Warthog ground attack planes and Reaper drones.

It also uses an aircraft carrier and air bases in Jordan and Gulf countries. Washington has deployed a wide variety of planes for its air campaign, from the F-16 fighter plane to the B-1 and B-52 bombers. 

- ...but also deploys special forces -

Washington has deployed up to 300 Special Operations Forces in Syria, namely to advise the Arab-Kurd coalition of the Syrian Democratic Forces and to help guide coalition strikes. 

The CIA also has a clandestine program to assist rebel groups fighting the Assad regime, mostly providing weapons directly to the fighters or indirectly via allied countries.

No U.S. soldier has been killed so far in Syria since the start of the intervention.

- U.S.-Russian military communication -

After the start of Russian strikes, the U.S. and Russian militaries set up a communications channel to exchange information on their respective air operations. Washington is quick to point out the effort does not reflect cooperation of any kind. 

One key objective is to avoid crashes between their aircraft.

- Russian strikes killing more civilians -

The United States accuses Russia of using unguided bombs, which are more likely to result in civilian deaths, while the Americans use precision-guided munitions to avoid such tragedies.

Toll counts by non-governmental groups show that Russian strikes have indeed been far deadlier for civilians than American ones.

Russian air strikes have killed nearly 3,000 civilians in Syria since October 2015, according to Britain-based Airwars. That's a higher toll than that caused by the coalition in Iraq and Syria since August 2014 (1,600-2,400 civilian victims).