BEIRUT • Russia and Syria have unleashed a coordinated assault by land, air and sea, seeking to reverse recent gains by rebel groups that were beginning to encroach on the Syrian coast, a critical bastion of power for President Bashar Assad.
Moscow said it had fired 26 cruise missiles at Syrian targets from naval vessels in the Caspian Sea, about 1,450km away, though it was not clear whether they had struck in the area of the ground offensive.
A Syrian general said the Russian intervention had weakened the militant Islamic State in Iraq and Syria (ISIS) as well as other armed opponents of Mr Assad.
But Washington said more than 90 per cent of Russia's strikes targeted the moderate opposition.
Nato yesterday voiced alarm at the escalating Russian military activity in the war-torn country.
"We will assess the latest developments and their implications for the security of the alliance," secretary-general Jens Stoltenberg said as he went into a Nato defence ministers meeting in Brussels.
"This is particularly relevant in view of the recent violations of Nato's airspace by Russian aircraft," he added.
Tensions between Russia and Nato member Turkey shot up this week after Russian aircraft infringed on Turkish airspace.
Although in its early stages, the coordinated attack on Wednesday has revealed the outline of a newly deepened and operationally coordinated alliance among Syria, Iran, Russia and the militant group Hizbollah, according to an official with the alliance, who spoke on condition of anonymity.
The official said the Russian intervention - a result of plans by the four allies over at least four to six months - had rejuvenated Syrian government forces and put to rest any doubts about Russia's commitment to the Syrian President.
Despite Western calls for his departure, Mr Assad remains in power more than four years into a war that has killed a quarter of a million people and displaced half the country. "No more questions," the official said in tones of renewed confidence and optimism. "Not at any level."
For Mr Assad's supporters and opponents alike, regionally and internationally, Russia's increasing willingness to throw its full military power behind him amounts to a game-changer.
For his supporters, it gives a much-needed respite to depleted ranks of fighters and bolsters morale. For his opponents, it means taking on a vastly stronger foe and severely constrains options - for instance, virtually ruling out the imposition of a no-fly zone or buffer zone along the border with Turkey.
Russia has focused its operations on the insurgent coalition known as the Army of Conquest, or Jaish al-Fatah, rather than ISIS, said the official from the pro-government alliance. This is because it is Army of Conquest positions that most threaten the crucial government- held coastal province of Latakia, while ISIS forces are further to the east and more easily contained.
Latakia is Mr Assad's ancestral home and the heartland of his fellow Alawites, who provide a critical bloc of support.
The assault seemed to focus on an area straddling northern Hama province and southern Idlib province, where insurgent command of high ground threatens the coast.
A number of times on Wednesday, insurgents fired advanced TOW anti-tank missiles, supplied covertly by the Central Intelligence Agency, at Syria's Russian-made tanks, leaving the impression of a proxy war between Russia and the United States. Rebel groups, including two that have received US aid, posted videos that show the guided missiles sailing towards approaching tanks and destroying them.
A US-led coalition has been carrying out air strikes against ISIS in both Syria and Iraq for months. Western countries support rebels fighting to oust Mr Assad.
There were air strikes elsewhere in Syria, according to SANA, the state news agency, which said that Syrian and Russian warplanes had worked together to attack targets in the city of Al Bab in eastern Aleppo province which has long been held by ISIS.
The ground operation will eventually widen to include new contingents of fighters from Hizbollah, which has long played a key role on the front lines, as well as the current configuration of Syrian forces backed by Russians in the air, according to the alliance official.
In addition, Iranian military advisers have been active on the ground in Syria.
There were no reports of Russians joining in the fighting, though an official refused to rule out the possibility of "volunteers" becoming involved.
NEW YORK TIMES, AGENCE FRANCE-PRESSE