Why Syria's war, after 400,000 deaths, is only getting worse

WASHINGTON - There is a basic fact about Syria's civil war that never seems to change: It frustrates any attempt at resolution.

Despite many offensives, peace conferences and foreign interventions, including this week's Turkish incursion+ into a border town, the only needle that ever seems to move is the one measuring the suffering of Syrians - which only worsens.

Academic research on civil wars, taken together, reveals why. The average such conflict now lasts about a decade, twice as long as Syria's so far. But there are a handful of factors that can make them longer, more violent and harder to stop. Virtually all are present in Syria.

Many stem from foreign interventions that were intended to end the war but have instead entrenched it in a stalemate in which violence is self-reinforcing and the normal avenues for peace+ are all closed. The fact that the underlying battle is multiparty rather than two-sided also works against resolution.

When asked what other conflicts through history had similar dynamics, Barbara F. Walter, a University of San Diego professor and leading expert on civil wars, paused, considered a few possibilities, then gave up. There were none.

"This is a really, really tough case," she said.

A conflict immune to exhaustion

Most civil wars end when one side loses. Either it is defeated militarily, or it exhausts its weapons or loses popular support and has to give up. About a quarter of civil wars end in a peace deal, often because both sides are exhausted.

That might have happened in Syria: The core combatants - the government and the insurgents who began fighting it in 2011 - are quite weak and, on their own, cannot sustain the fight for long.

But they are not on their own. Each side is backed by foreign powers - including the United States, Russia, Iran, Saudi Arabia and now Turkey - whose interventions have suspended the usual laws of nature. Forces that would normally slow the conflict's inertia are absent, allowing it to continue far longer than it otherwise would.

This is why, according to James D. Fearon, a Stanford professor who studies civil wars, multiple studies have found that "if you have outside intervention on both sides, duration is significantly greater."

Government and rebel forces are supplied from abroad, which means their arms never run out. They also both draw political support from foreign governments who do not feel the war's costs firsthand, rather than from locals who might otherwise push for peace to end their pain. These material and human costs are easy for the far richer foreign powers to bear.

The ground battles+ also include Kurdish militias, who have some foreign backing, and the Islamic State, which does not. But pro-government and opposition forces are focused on one another, making them and their sponsors the war's central dynamic.

No one can lose, no one can win

Foreign sponsors do not just remove mechanisms for peace. They introduce self-reinforcing mechanisms for an ever-intensifying stalemate.

Whenever one side loses ground, its foreign backers increase their involvement, sending supplies or air support to prevent their favored player's defeat. Then that side begins winning, which tends to prompt the other's foreign backers to up their ante as well. Each escalation is a bit stronger than what came before, accelerating the killing without ever changing the war's fundamental balance.

This has been Syria's story almost since the beginning. In late 2012, as Syria's military suffered defeats, Iran intervened on its behalf. By early 2013, government forces rebounded, so wealthy Gulf states flooded support to the rebels. Several rounds later, the United States and Russia have joined the fray.

These foreign powers are strong enough to match virtually any escalation. None can force an outright victory because the other side can always counter, so the cycle only continues. Even natural fluctuations in the battle lines can trigger another round.

Over the past year, for example, the United States has supported Syrian Kurds against the Islamic State. As the Kurds grew strong, this alarmed Turkey, which is fighting its own Kurdish insurgency. This week, Turkey intervened to seize the Syrian town of Jarabulus, backed by the United States, in part to prevent Kurds from taking it first. (The United States backed this effort, too, in case the alliances weren't complicated enough already.)

"We tend to think this is as bad as it can get," Walter said. "Well, no, it could get a lot worse."

War's structure encourages atrocities

Syria has seen repeated indiscriminate mass killings of civilians, on all sides. This is not driven just by malice, but by something more powerful: structural incentives.

In most civil wars, the fighting forces depend on popular support to succeed. This "human terrain," as counterinsurgency experts call it, provides all sides with an incentive to protect civilians and minimize atrocities, and has often proved decisive.

Wars like Syria's, in which the government and opposition rely heavily on foreign support, encourage the precise opposite behavior, according to research by Reed M. Wood of Arizona State University, Jacob D. Kathman of the State University of New York at Buffalo and Stephen E. Gent of the University of North Carolina.

Because Syria's combatants rely on foreign sponsors, rather than the local population, they have little incentive to protect civilians. In fact, this dynamic turns the local population into a potential threat rather than a necessary resource.