The US did not lose the war in Vietnam; the US lost the war in Vietnam because going into that war started a civil war in the US. The same thing happened to France in Algeria.
When the enemy poses an immediate threat to a representative democracy, such as for example, Germany and Japan did just before WW II, it is relatively easy to unite the people in a representative democracy and go to war.
The problem comes up when the enemy does not threaten a representative democracy directly. In that situation, the politicians may decide to go to war because they feel “it is the right thing to do”, “because leaders are elected to make such decisions” and so on. But they decide without really knowing if the country is ready for war, or if the majority support or oppose the war. They proved that with the Vietnam War and with the Algerian War.
In representative democracies the executive and legislative do not really practice “government of the people, by the people, for the people”. What they practice is, in the best of cases, what the leadership believes is government for the people.
Unfortunately, sometimes, the elected leadership does not even do that; they practice government for themselves, to get re-elected and to help the lobbies and pressure groups who “support” the politicians, in exchange for friendly legislation and other gestures. It is no wonder so many people in representative democracies do not trust politicians.
It is absurd than in a democracy the elected representatives can make huge decisions without the explicit support of the majority of the people.
As a result we have wars like the Vietnam War splitting the US, the Algerian War which splitted France, and other wars. Those wars were decided by the politicians without the explicit approval of citizens. That is why the US and France had to give up fighting, but they did it a bit late, after tens of thousands of Americans and Frenchmen died.
If there had been binding referendums in the US and in France, the people would have decided to go or not to go to war. The losers would have accepted their defeat because it would have been a democratic defeat. Besides, the losers would also know they could continue working towards another referendum on the same issue, perhaps they will would next time, such is democracy.
It is important to understand that decisions made by leaders elected democratically are not democratic decisions, they are autarchic decisions, and that is the Achilles Heel of representative democracy. It leads to bad decisions, not just with respect to war; it also affects the education system, health care, investments in infrastructure and the military, etc. Autarchic decisions do not benefit from the extensive formal and informal debates and different inputs that are at play in referendums.
Direct democracy is truly “government by the people” because the people decide on issues, they don’t just vote. In a direct democracy the elected representatives no longer have the final say war and many other issues.
Some people oppose direct democracy because they fear voters could make “emotional” decisions, (they mean “irrational” decisions), that demagogues could deceive them, etc. The facts show otherwise.
The only two experiences humanity has had with direct democracy; that of the Ancient Greek city-states, and now Switzerland, demonstrate the opposite; there was no more rational government in Antiquity than the direct democracy of the Greek city-states.; no government by oligarchs, priests or kings even came close. Switzerland also shows now how the Swiss voters make, time after time, better decisions, more rational decisions, than the elected politicians in direct democracies.
Anyhow, in representative democracies, the people can also make emotional and irrational decisions when they vote. Several factors favour that; it is impossible to judge how those we elect will behave. Therefore, is it rational to give someone the power to decide on our behalf before even knowing what the issue is?, it makes no sense.
Another problem in representative democracies is that voters are not responsible, and do not feel responsible, for the decisions politicians make. This means that it is easier to vote for whoever promises the most. In direct democracy, politicians can not promise much because they can not do much, they don’t have the power.
History also shows the leaders of representative democracies make irrational decisions too.
In a direct democracy voters are forced to be rational because voters know they are responsible for the effects of their decisions; this makes voters extremely careful and prudent. Perhaps that is why Switzerland is a neutral country. The Swiss have been showing prudence for decades, the Greeks showed it much earlier.
Some people say direct democracy is “too slow”; Switzerland has not been slower than representative democracies in facing the current pandemic. It is just one example. The executive, even the legislative bodies, can also be given special powers by the people to act in emergencies.
It is true that when the people decide, some decisions take more time, but this improves the quality of the decisions and, also very important in a democracy, the social acceptance of decisions. In a direct democracy, decisions often take longer because there is more analysis and deliberation which lead to better decisions.
So, if you want your country to be less divided, with more trust in the politicians, and make better decisions, you should consider doing whatever you can to turn your country into a direct democracy.