(HOST) After several months of relative quiet in Iraq, violence appears to be on the upswing again. This morning veteran ABC News foreign correspondent and commentator Barrie Dunsmore looks at how Iraq might affect this year's Presidential election outcome.

(DUNSMORE) The Korean War was in its third year during the 1952 Presidential campaign, and the Democrats did not have a clear plan to end it. Republican candidate and World War II hero Dwight Eisenhower promised nothing, but two weeks before the election he said he would go to Korea. That cemented his victory. Even before he was sworn in, he did go to Korea and after three days decided there was no point in continuing the war. By July 1953 an armistice was signed which continues to this day.

In 1968 the Vietnamese War was raging and the Democratic Party was sharply divided because of it. Republican candidate Richard Nixon implied that he had a secret plan to end the war. He defeated the divided Democrats, and the war continued for another seven years.

In 2008 America is again engaged in an unpopular war, this time one initiated by a Republican President. Both Democratic candidates, Senators Obama and Clinton, say they will begin to withdraw combat troops within weeks of their election. The presumed Republican candidate, Senator John McCain, is committed to victory and will keep American troops there as long as it takes. Given the mood of the country and the fact that a substantial majority of the people want the Iraq war to be over, it would seem the Democrats should have a substantial edge. That may or may not be true.

It seems to me much will depend on what happens in Iraq itself over the coming months. If violence remains at about its present level, that should marginally help the Democrats because other issues like the economy will then be more in play. But if the killing starts to rage again and there is a renewed danger that the whole region may go up in flames, that is likely to benefit John McCain. His heroic record as a prisoner of war does not necessarily imbue him with great military wisdom - but it does translate into high marks for courage and determination under actual fire. That's something neither Democratic candidate can claim.

It's important to remember that while both the Korean and Vietnamese wars were very unpopular, in each case Americans were also struggling with the notion of defeat and were searching for some form of peace with honor.

With his huge wartime credibility, Eisenhower was able to provide some semblance of honor as he accepted a truce that was actually a military stalemate. Nixon also promised an honorable peace. Of course, when the fighting finally ended it did so in defeat with precious little honor attached.

Nine months before the voting it is too early to say whether the Korean or the Vietnamese model is more likely to prevail in determining America's future course in Iraq. But even given the substantial anti-war mood of 2008, one should not underestimate the power of the illusion that somehow there can be a good ending to a bad war.