Mary Dejevsky: Keep out of the conflict in Damascus

Whatever happened at the national security building in Damascus this week – something so cataclysmic that even the beleaguered regime of Bashar al-Assad had to admit the loss of three members of its inner circle – it altered the balance of forces in Syria at a stroke. It prompted devil-may-care jubilation from sections of the opposition and a new tone of defensive flag-waving from the leadership.

It is that tone, quite as much as the attack on such an inner sanctum itself, that shows there can be no going back. And as the US Defence Secretary warned of Syria "spinning out of control", the Russian Foreign Minister spoke of a "decisive battle", and news organisations modified their heading from "violence" to "civil war", it was clear that outside perceptions, too, had changed. All right, perhaps one opposition agent struck lucky. It's not unheard of for luck to change the course of history.

If the situation was perilous before, however, it is many times more perilous now. Before Wednesday, it was possible to believe that there was time: time for the Russians to sign up to international sanctions; time for Assad to accept the inevitable; time for a fractious UN to cobble together some sort of political transition. But as the UN Secretary General called on Security Council members to "shoulder their responsibility and take ... action with a sense of urgency", his unmistakeable meaning was that time was running out. Syria had reached its tipping point.

Identifying the precise moment when a regime reaches the point of no return is rarely simple. Consider how long it took the United States to cast off the Egyptian President, Hosni Mubarak. In the end, Mubarak's fate was sealed by his own military, which essentially effected a coup d'etat in favour of the disparate opposition.

It was just about possible to envisage a similar start to the transition in Syria, with the top brass summarily changing sides. But the decapitation of a part of Assad's defence structures could complicate even such a short-term remedy. If Syria's military now splits, pro- and anti-Assad groups may fight for power. Comparisons are already being made with the Balkans. That prospect is one reason why the handwringing appeals for "the West" or the "international community" or, well, anyone, to intervene have grown more insistent – and why they still need to be resisted. Syria threatens to become very messy; even more than it already is. If the US, Russia and China take different sides, if Iran decides to stake a claim, too, the result could be the sort of proxy war that was mostly consigned to other continents during the Cold War.

Other people's transitions are best viewed from the margins. The way the US, Britain and others became bogged down, first in Afghanistan and then in Iraq, illustrate the perils of interfering in, or even triggering, someone else's war. The danger is not simply the inevitable sacrifice of your own citizens' lives, but of exacerbating the existing conflict. That is why the first President Bush decided against turning the liberation of Kuwait into a punitive mission against Iraq and Saddam Hussein. He was right, and his son was wrong.

What is now almost universally referred to as the Arab Spring is a historic transition that is comparable, in its scale and implications, only – in recent memory – with the demise of communism in Europe and the end of apartheid in South Africa. Whole systems have been brought down; but the rebuilding has barely begun. Few would venture to forecast what the region will look like this time next year, let alone in five, 10 or 50 years' time. The very idea that outsiders, however well-intentioned, should plunge in on one side or other is as presumptuous as it is unwise.

As events that seemed to rise out of nowhere, came burdened with hope, and whose results so far may be judged better than expected, the reunification of Europe and the end of apartheid may have something to teach – not to the prime players of the Arab Spring, who must forge their own path, but to those national and international leaders looking on anxiously from outside. When the stirrings that culminated in the collapse of communism began in Hungary, there was scant understanding that the future of the whole region was in flux. There had been uprisings before, but they had all been suppressed. The tipping point is not necessarily reached even when huge numbers descend on to the streets, but when ordinary people and key individuals believe that the existing regime is doomed. They may slip away quietly, or they may join the opposition noisily, but it is they, not foreigners – however committed – who make the revolution. Without an internal dynamic for change that change will not be sustainable.

The end of communism, like the end of apartheid, held huge risks. The fall of the Berlin Wall, spontaneous and miscalculated though it might have been, represented the de facto abrogation of the post-war settlement that had underpinned almost half a century of peace. The dissolution of the Soviet Union was in part precipitated, and accompanied, by the complete collapse of the supply system. Violent recriminations were envisaged there, as in South Africa.

To their credit, or perhaps because the events they were witnessing were at once so unimagined and so monumental, the leaders of the time – including George Bush, Helmut Kohl and, let it not be forgotten, John Major – resisted the temptation for national land-grabs and busied themselves with trying to avert some of the conceivable dangers. They included famine, waves of refugees and a mass of nuclear weapons out of control.

Their good fortune was that almost everywhere alternative governments waited in the wings. Even in these relatively propitious circumstances, however, the transitions have generally taken longer and suffered more setbacks than many hoped. And the very worst results have been in places where outsiders tried to seal the fate of a tottering regime. Those of us outside the Middle East are fortunate to be witnessing one of the great historical shifts of our age. What we are seeing is by turns exhilarating, uplifting and brutal. But we should not aspire to be more than benevolent spectators, lest we tip the delicate balance for the worse.