Moreover, its also the quality of the troops, leadership and political control/structure. I wouldn’t blame the French for what occured in Indochina, the americans didn’t fare much better. That being said, the french couldn’t win a war in the 50s/60s when it was a stone throw away, algeria. You would have thought the French after being occupied by the Germans for a few years would have a bit more sympathy for the people they oppressed. Algeria and the subsequent military coup by French officers that lead to the collapse of the Fourth Republic.
Vietnam could have gone much differently. Ho Chi Minh initially loved and was friend of the US during WW II. After the war Ho thought freedom for his country would be kinda nice, the French figured it was back to the good ole days of colonial rule. Can you imagine after WW II the French figured they had the right to occupy another nation, lesson lost on them I guess. In fact, Ho based their 'declarition of independence on the US version. Ho was actually given 2 american made colt firearms by a macarthur perhaps? Maybe not him but some important US general, I shall have to google it!
Had the French been told that NO, Vietnam will no be your slave nation, in fact, we will help it to become a democracy. If only there was a marshall plan for the far east after WW II. I wonder what kind of rate of return you would have gotten for some investment in Vietnam in the late 40s and 50s in the form of nation building?