The invasion of Iraq and the ensuing Arab state revolutions enabled the rise of Islamic State extremists, unleashing chaos and terrorism that has spread far from the region, Sawers said at the AIC2016 on April 8.

“The big lesson of Iraq…was that order itself is a precious thing, however revolting the leader (Saddam Hussein) may be” Sawers said. “If you replace order…you end up with chaos and violence.”

Based on that lesson, Sawers advocates patience in managing troublesome regimes - as difficult as they can be to endure, forcing change would only make things worse.

North Korea, for example, routinely threatens and provokes its neighbors, which is a real problem for the region. But the regime is likely to collapse on its own at some point, and China prefers to try to “manage” Kim Jong-un, who provides a buffer to the US ally South Korea, rather than accelerating his downfall, Sawers said.

“China is going to play a very important role in managing the end of the regime, whenever that is,” Sawers said. “I can’t tell you when it will collapse, but it will collapse at some point, and we’ve got to be ready for it.”

On China’s northern border rests another troublesome leader in Vladimir Putin, who has irritated Western leaders by annexing Crimea and meddling in the Syrian civil war. But Putin’s ability to project power is dwindling with weak oil prices and a shrinking economy, exacerbated by international sanctions.

“That doesn’t mean there’s a better Russia just around the corner,” Sawers said. “I think if there’s a change in leadership in Russia, it could well be for the worse.”

A collapse in state authority in Russia would lead to civil chaos, a rise in organized crime, and the potential for nuclear materials to wind up in the hands of nefarious people or terrorists, Sawers said.

“Putin may be a challenge to Europe, but its better a challenge we know and can manage than not,” he added.

Another regime that seems destined to fall is in Iran, where a growing number of people want to move beyond revolutionary rhetoric and re-engage with the rest of the world, Sawers said. The result could be a boon for growth in the Gulf region—a smaller scale version of China’s impact on its neighbors in Asia.

“A lot is going to happen when (Supreme Leader Ali) Khamenei dies. We don’t know when that will happen,” Sawers said. “Iran is gradually emerging from a period of dominance by those committed to perpetual revolution.”