Apart from the defeated Italy and the relatively irrelevant Spain and Portugaul, the two remaining colonial powers in Europe (France and England) did all that was conceivably possible to keep their colonial empires. Political thinkers believed "Eurafrica," or the continued subjugation of the African continent by european powers, was key to securing the resources necessary to reconstruct in the postwar era.

However, it soon became evident that maintaining colonies was an immensely stupid and resource draining activity. In his book titled European Integration, Mark S. Gilbert illustrates how British insistence on maintaining a military presence on the European Continent, in Africa, and in Asia leads to Great Britain not only to suspending Pound convertibility to the dollar in 1947 (effectively going into default) but also missing out on the entire early european integration process: just to give an example, the Treaty of Paris is item number five on Atlee's cabinet agenda in April 1951 because previous four items have to do with communist militias in Indonesia which the British army can't hope to defeat but insist on trying anyway.

Although Churchill narrowly clawed his way back to the premiership in the fall of 1951, Atlee had already set up the modern British welfare apparatus that couldn't be dismantled. When faced with choosing between the British welfare system and colonialism, Atlee chose a third road (default) but afterwards, when it came to picking between international engagements and welfare guess what successive British governments did? One by one, they disengaged abroad to focus on spending at home. Piece by piece the United Kingdom lost its empire.

The same goes for France. The Algerian War nearly sparked a military coup; hardly the signs the French were getting rich off of colonial resources, in spite of what the proponents of "Eurafrica" might have thought ten years before. Indeed, if anyone other than De Gaulle had won the 1958 election, France might very well have descended into civil war.

The dominant mantra on the European continent led to a slow, losing battle against their colonies who wanted independence.

The French initially made no response to the Vietnamese declaration of independence, but the emergence of a nationalist government led the jubilant de Gaulle to send General Leclerc in to reestablish French power.

But this was just a flash of nationalistic over-reach by a man who always had an exaggerated sense of the French glory, and excessive desperation to restore her honour after he was eventually accepted as the rightful leader of France.

For the vast majority of the subsequent years to 1954, the French were deeply ambivalent about their committment to Vietnam, but in parallel with the US later, no government wanted to be the one to accept defeat by an Asiatic and communist enemy.

It's wrong to say the Vietnamese independence movement was especially violent, the fighting escalated on both sides according to the resources available (which by the early 50s were considerable: the Vietnamese gained Chinese support with Mao's victory in China, and the US started supplying the French with arms and money after the Korean War broke out). The fighting was largely confined to the north of the country. However, the Viet Minh were especially adept, like many communist movements, to usurp the French as a government. So they killed governors and bureaucrats and set out to show the Vietnamese people that they were not just a military force.

A really good book on this is Embers of War by Frederik Longuvall.