A surprisingly effective counteroffensive by the Syrian government in recent weeks is reminding rebels, foreign intelligence services and the media alike that the fortunes of war are wildly unpredictable.

For most of Syria's 28-month-long civil war, it has been widely assumed, at least in the West, that dictator Bashar al-Assad was a walking dead man when it came to hanging on to power.

Optimists were highly vocal in insisting the end wouldn't be long in coming. Surely, they felt, not even resuscitation efforts by Syria's lone allies (and arms suppliers), Russia and Iran, could save the thuggish family-run regime from ignominious collapse.

Well that's not how it's turning out. Right now it's the disunited and fractious rebel alliance that appears to be increasingly on the defensive while Assad's far better armed and notoriously ruthless elite forces are gaining ground.

"Strategically, the regime has the advantage — taking the initiative, using new tactics, opening up counteroffensives or new fronts over the last two-to-four months," says Yezid Sayigh, senior analyst with the Carnegie Middle East Centre in Beirut.

He is just one of several Syria watchers now who are seeing dramatic shifts on the ground.

Some are even scrambling to update the odds in Assad's favour, at least for the coming months.

Revised intel

Among the red faces at the moment are the Syrian analysts in the German Federal Intelligence Service (BND). Just last year they were telling politicians that Assad would likely fall in early 2013.

Now, intelligence chief Gerhard Schindler, according to Der Spiegel magazine, is warning his bosses that Assad's new offensives might, by year end, retake the critical south, which would be a huge loss to the rebels.

Even the most hardline U.S. politicians, like Senator John McCain, who have been demanding a U.S.-imposed no-fly zone over Syria, now see the once doomed dictator actually tightening his grip on power.

Just back from a surprise trip into Syria to meet rebel leaders, McCain warned that the insurgents are being heavily battered. "We are seeing, unfortunately, a battlefield situation where Bashar Assad now has the upper hand, and it's tragic, while we sit by and watch."

Of course one reason why President Barack Obama and other Western leaders are staying well on the sidelines in this conflict may be precisely due to the intelligence reports warning that Assad is a far harder nut to crack than previously thought.

That and the fact that the rebels are no closer to forming a winning, united or even trustworthy insurgency.

This is not to say, let's be clear, that a resurgent Assad is now bound to win in the long run. Rather, it is that a tyrant wounded, but not destroyed, is a profoundly dangerous foe.

What this likely means is that we are now likely to witness a different type of war, perhaps even bloodier, as the embattled regime seeks to win back the 50 per cent or so of the country that it lost or abandoned to the rebels in the early stages.

In other words, a war that may drag on for years.

So what happened? What accounts for Assad's survivability, apart from sheer brutality, in the face of so many eager predictions of his doom?

Some of these factors have been well examined, including the fact that the Assad family has been able to count on the support of its own Alawite sect, as well as a Christian community of about 2.6 million and, indeed, moderates from other religious groups who fear fundamentalist Salafists and even al-Qaeda elements among the rebels.

The large urban merchant class and civil servants no doubt also feel they have a stake in regime survival.

In short, Assad has deep, even if minority, wellsprings of support at home to go with an increasingly steady flow of help from three critical friends: Russia, Iran and, more recently, Hezbollah, the Shia Islamic movement (military and political) based in Lebanon.

Assad's order of battle

Still, important as these pillars are, they could not alone have saved Assad had he not been able to count on perhaps the most vital if often overlooked source of power at his disposal — the unexpected cohesion of Syria's military, especially its army.

Despite a large number of defections, the Syrian military remains one of the largest and best trained forces in the Arab world, at around 290,000 strong.

Early in the war, it was believed the army would disintegrate as most of its conscripts were Sunni (who are the majority in Syria and the source of the rebel opposition) while 80 per cent of the officer corps were minority Alawites, a Shia offshoot.

But according to a recent in-depth study by the Washington-based Institute for the Study of War, the Syrian army is still a "disciplined and motivated force."

What's more, when you look at the Syrian order of battle, it seems that Assad has not tried to test the loyalty of most of the army units, and has instead left all the toughest fighting to what amounts to a Praetorian guard of trusted elite units, the 4th Armoured Division, Republican Guards, and special forces.

The Syrian army responded poorly at the start of the war, in part because its doctrines dated back to earlier, Soviet-style training, which had prepared it for a conventional land war against neighbouring Israel.

Since then, however, it has reshaped its security forces, given them more modern arms from Russia and Iran, and adopted a more flexible counterinsurgency style of warfare.

While the UN says there are reasonable grounds to suspect the regime has used limited chemical weapons, its conventional arsenal is terrifying enough.

Rebels complain that government's precision weapons and artillery are more accurate, while armed helicopters, SU-22 strike aircraft and, since December, even Scud missiles have been pounding rebel positions even in civilian areas.

The key problem for the rebels is their lack of secure logistics and their own flimsy command structure, which is distrusted in the West.

In a long war of attrition like this, the side best supplied has a vast advantage. Assad's military has the benefit of military supplies from Moscow and Tehran, and has held critical supply routes open against rebel attack.

Now, as French Foreign Minister Laurent Fabius warned recently, the arrival of up to 4,000 Hezbollah fighters in Syria to fight for Assad, many of them veterans of fierce battles with Israeli forces in 2006, gives him a new edge as he turns his attention to reducing rebel territory.

Lest anyone doubt the relevance of this warning, Fabius added "When you have fighters that are really well-armed, that are prepared to die and they are several thousand, that makes a difference."

I'd say that's one prediction, at least, that you can probably bank on.