How Vladimir Putin plays Winnie-the-Pooh to Bashar al-Assad

Christopher Robin and Winnie-the-Pooh had an exceptionally close alliance: one party would routinely submit to being dragged down the stairs by the other: bump, bump, bump.

The comparison might not immediately leap to mind, but some of the reaction to the agreement to rid Syria of its chemical arsenal could spring from the A Milne school of international diplomacy.

President Vladimir Putin is implicitly cast as Christopher Robin and Bashar al-Assad as his obedient teddy bear.

We are assured that Russia, with its prestige at stake, will now compel Syria's leader to hand over his 1,000 tons of poison gas, in accordance with the fastest timetable ever for disarmament on this scale.

Nicholas Burns, a professor of international politics at Harvard and once a leading US diplomat, writes that America "will have every right to pressure its Russian co-pilot on the deal to make Assad honour it".

But can Russia "make" Assad surrender his arsenal? Even if we assume that Mr Putin genuinely wants this agreement to work, history still cautions against the assumption that Russia can bend Assad to its will.

From China's tortuous alliance with North Korea to America's with South Vietnam, the relationship between a Great Power and a supplicant dictatorship is often more complicated than it might appear.

Telling the Christopher Robin member of the duo apart from the Winnie-the-Pooh can be surprisingly difficult. After all, a Great Power that gets itself into the position of being the only friend of a beleaguered regime runs one big risk: it can simply be taken for granted.

The moment arrives when the Great Power has invested so much diplomatic - and often financial - capital in preserving its odious friend that changing course becomes too difficult, or just too humiliating. And the dictator will always work this out.

One day, he realises that his powerful protector has reached the point of no return and will back him come what may.

True, this calculation will always be a gamble, but besieged autocrats are not shy about taking risks or pushing boundaries.

The signs are that Russia and Assad have reached this stage. The poison gas attacks of August 21 might serve as "Exhibit A" for this thesis.

We can be sure that Mr Putin would not have wanted Assad to drench areas of his own capital with the sarin nerve agent, and yet the evidence suggests that exactly this happened.

And Russia's reaction? Instead of dropping Assad, the Kremlin proclaimed his innocence: only yesterday (Tuesday), Sergei Lavrov, the Russian foreign minister, repeated his line that Syria's rebels gassed the suburbs of Damascus - an accusation for which there is zero credible evidence.

But Moscow has grown accustomed to being manipulated by Assad. When Syria's revolt began in 2011, Russia sensibly urged him to negotiate with his enemies and agree a programme of political reform. Assad brazenly ignored his protector.

In January, Dmitry Medvedev, the Russian prime minister, disclosed how Assad had consistently spurned the Kremlin.

"I have personally called Assad several times and said: conduct reforms, hold negotiations. In my view, unfortunately, the Syrian leadership is not ready for this," he said.

Russia's response to being ignored by its client was to veto two United Nations resolutions on his behalf and continue supplying him with weapons.

If Assad now breaks the deal to hand over his deadly gas by June next year, experience suggests that Russia will allow him to get away with it. If the Kremlin could not stop him from using chemical weapons, why should Russia be able to guarantee that he will surrender them? On the Security Council, China serves as Russia's unofficial partner when it comes to shielding dictators.

As the only friend of North Korea, however, China knows the sensation of being treated like Winnie-the-Pooh by a rogue regime.

The gulf separating China from North Korea when it comes to economic strength and military might is almost inconceivably wide.

And yet the Kim family dictatorship blithely ignored China's insistence that North Korea must never develop a nuclear weapon. Once the Kims had built their bomb, China ordered them never to conduct a test.

Whereupon Pyongyang carried out three nuclear tests, in 2006, 2009 and in February this year. Did China respond by stopping the aid that serves as North Korea's lifeline?

To do so would almost certainly have caused the collapse of the pariah state, sending millions of refugees into China. It would also have been a confession of failure, made more humiliating by the fact that propping up North Korea has been a fixed goal of Chinese foreign policy ever since the Communists seized power in 1949. China prefers to fume impotently.

This emotion is more familiar to America than it might care to admit.

Throughout the Cold War, the superpower was artfully manipulated by obnoxious clients.

Perhaps the most brazen was South Vietnam, a regime that owed its existence to American military sacrifice, and yet managed to be consistently troublesome.

From 1965-67, when America sank irredeemably into the Vietnam quagmire, the leader of the South was Nguyen Cao Ky, a man who cheerfully declared Hitler to be his hero, adding: "We need four or five Hitlers in Vietnam."

So history delivers a stark warning: anyone who believes that a Great Power can automatically "deliver" its client risks being dragged down a painful staircase: bump, bump, bump.