Five years after the start of the Syrian conflict we look at five ways it has changed the world.
1. Rise of Isis
It was in the vacuum of the deteriorating Syrian conflict that a little-known and horrifically violent branch of al-Qaeda grew into the foremost terror group on the planet. In 2014, Isis (Islamic State) completed its takeover of the eastern Syria city of Raqqa and went on to conquer Iraq's Mosul. It has absorbed weapons, wealth, and personnel along the way. Isis has sparked deep anxieties in the region and around the world by slaughtering minorities, institutionalising sex slavery, vanquishing state armies, and killing opponents in gruesome spectacles of violence. It destroyed heritage sites, such as temples in the ancient city of Palmyra, and fuelled the global antiquities trade.
2. Resurgent Russia
"There is one man on this planet who can end the civil war in Syria by making a phone call, and that's Mr Putin," British Foreign Secretary Philip Hammond said recently. Russian President Vladimir Putin, who today has ordered the start of the pullout of the Russian military from Syria, has established a renewed Middle East foothold after watching for years as the United States called shots in the region. Last September, after showering arms, advisers, and economic assistance on President Bashar al-Assad to insufficient effect, Putin sent his air force to pound the Syrian Government's opponents. The recent ebb in violence is largely because Russia dictated it. Russia's designs for Syria are still veiled, but whoever leads Syria next will largely owe their chair to Putin.
3. Europe destabilised
When Europe fashioned its open border agreements late last century, it did not anticipate over a million migrants - mostly refugees from Syria - in one year alone, as happened in 2015. Thousands have died trying to cross by sea. The stream of refugees, which continues unabated, has brought on both generosity and xenophobia, ultimately shaking the open-border arrangement to the core. The Isis attack on Paris in November, though largely perpetrated by French and Belgian nationals, sparked security recriminations across Europe and boosted nationalist politicians. In the United States, Republican front-runner Donald Trump shocked many by proposing a ban on Muslims entering the country.
4. Neighbours subverted
Europe's migrant crisis is dwarfed by the wave of displacement that has washed into Syria's neighbours. Turkey, Lebanon, and Jordan alone host around 4.4 million refugees from Syria; in Lebanon, they make up more than one-fifth of the population. The Syria conflict has also ensnared militias and state actors across the region, destabilising fragile neighbours like Lebanon and reawakening ethnic tensions in Turkey, where the Syria conflict has provoked concerns of a civil war with the Kurds.
5. Iran ascendant
The Syria conflict has rebalanced regional axes of power. Predominantly Shia Iran's sphere of influence now extends from Beirut to Tehran, with dependent governments in Baghdad and Damascus. The commander of the elite Quds Force of the vaunted Revolutionary Guards, General Qassem Soleimani, has visited Russia and is often seen directing deployments in Syria and Iraq. Iran has militias in both countries said to operate outside sovereign command structures. In Lebanon, Iran is powerfully represented by Hizbollah, the party-militia hybrid that expelled Israel from the south of the country in 2000. It has sent thousands of fighters to prop up Assad. Israel glumly watches its nemesis training with modern artillery alongside Russian and Iranian contingents. Saudi Arabia is struggling to maintain support for the mainly Sunni rebels it backs in Syria while also fighting Iran-supported Shia rebels in Yemen.