As the war in Iraq seems to be continuing with no end in sight, comparisons have increasingly been made with the US experience in Vietnam.

Many of the same questions asked then are being asked again now.
When will the conflict end? Has the United States got itself stuck in another quagmire? Is the war in Iraq winnable at all?
Not everyone, however welcomes these comparisons.
In this series Jonathan Marcus explores the impact of these two conflicts on the american political psyche.
Part Two - The effect on the US military
In the second and final part of the series the BBC's diplomatic correspondent, Jonathan Marcus, compares the impact of the two wars on the American military.
The US army changed drastically following the war in Vietnam, would their be a similar impact on the politics of war after Iraq?