BARBARA F WALTERA striking fact about civil wars is that the outcome is often clear months or even years before the war ends. Jefferson Davis knew he would lose the American Civil War after the fall of Atlanta, yet continued to fight to the end. Muammar Gaddafi almost certainly knew that he would lose the war in Libya as soon as Nato assaults began, yet he continued to fight. The same is true of President Bashar al-Assad of Syria.

History has shown that determined leaders will continue to fight a civil war even if they know they will eventually lose. President Assad continues this tradition as he engages in his own costly march to defeat. Assad will not emerge victorious from this war. This was known as early as February 2011 when both the Director of US Intelligence and the CIA testified to the US Senate that Assad would not weather this challenge. If it is true that Assad will lose this war, why does he continue to fight? Assad continues to fight for two reasons. First, he knows he cannot negotiate his way out of this war. Theoretically, a negotiated peace settlement that offers members of the Free Syrian Army (FSA) some form of power-sharing in exchange for peace should be possible. Civil wars have ended in successful negotiated settlements in places like Nicaragua, Mozambique and Cambodia.In reality, a negotiated settlement in this case will be viewed as untenable by both Assad and the FSA.

From Assad's perspective, any real offer to share power would be tantamount to a decisive defeat since demographics strongly favour the Sunni majority at the expense of his minority Alawite faction.Agreeing to open up the political process to a group that represents 70 per cent of the population would be equivalent to Assad agreeing to a minority position in the new government. Any deeply unpopular dictator would know this would leave him vulnerable to imprisonment or death at the hands of a vengeful population. Even if Assad were to agree to significant political reform, the opposition has its own legitimate reason to reject settlement.

Assuming they could unite, why would Sunnis and Christians trust that Assad would continue to share power once they laid down their weapons? Violence and the continuing threat of violence is the only tool the FSA has to keep Assad in line and they will almost certainly be deeply sceptical of any promise by Assad to change. Assad could voluntarily cede power, spending the rest of his days in comfortable exile. But this is the second reason Assad continues to fight. Assad knows that a safe, comfortable exile is not an option for him. In the past, hated dictators have sometimes chosen exile when defeat seemed likely. The Shah of Iran did it in the 1970s, Ferdinand Marcos did it in the 1980s and Ben Ali did it in 2011. This option isn't open to Assad and this is what makes fighting to the finish attractive to him.

Assad cannot go into exile because exile leaves him highly vulnerable to prosecution at the hands of the International Criminal Court (ICC). Assad's problem is that he signed the Rome Statute of the ICC, giving the Court the right to prosecute him if he engages in crimes against humanity - something he has clearly done over the last two years.In fact, Secretary of State Hillary Clinton publicly confirmed last year that Assad could be prosecuted for war crimes. This places Assad directly in the sightline of the ICC. Assad could seek refuge in states that have not signed the Statute, such as the United States, Cuba, Saudi Arabia, Zimbabwe or Sudan. But the list of non-signatory states is small and most are either hostile to him, or so unstable that they cannot guarantee his safety over time.

So what will happen? History suggests that Assad will continue to fight with the aim of decisively defeating the rebels. He will hope that Iran and Russia will continue to support him and that the international community will not intervene. But time is not on his side. Continued war and economic sanctions will make his regime weaker.This decline may convince him to eventually accept a compromise settlement, but this offer is likely to be rejected by an opposition that does not trust him. Exile isn't a good alternative because few states are likely to accept him or credibly promise to protect him. The most likely outcome, as it was with Gaddafi, is defeat and death.

This is not a bad option for Syrian citizens and most of the rest of the world. Syria will get a new government under majority Sunni leadership, the US and the West will face a less hostile set of leaders, and the Sunni/Shia balance in the Middle East will come closer to be reinstated. Military and financial aid to the rebels could hasten this outcome. But anyone who believes that Assad will eventually agree to negotiate, or leave power quietly, ignores the strong incentives he has to fight to the death. Barbara F Walter is Professor and Associate Dean, Graduate School of International Relations and Pacific Studies, University of California. An expert on civil wars, conflict resolution and ethnic conflict, she is the author of Committing to Peace: The Successful Settlement of Civil Wars.