Because it is a complex situation, and military power superficially used does not generate the results seen in the movies.
I think there are important differences between the American Civil War and the Second World War and Vietnam or Yemen.
Most people understood why the Civil War and the Second World War were fought.
In the case of Vietnam, it was very different. Vietnam did not attack the USA. It did not threaten much of the world. It was a local problem caused by decolonisation mixed with the Cold War. The US supported the South Vietnamese dictatorship against the Stalinist North Vietnamese dictatorship. Hardly motivating.
In the case of Yemen, it would be similar: it is problematic for shipping companies, which means higher costs for them (and therefore for consumers). But killing a lot of people to keep a shipping lane open?
There are people who do not even want to help Ukraine to defend itself against Russia (without sending troops, only weapons and money!)... And Russia is threatening many neighbouring countries and is therefore a real problem. There a lack of support could mean that sending troops would be necessary, because it is likely that a successful Putin would attack more countries (he attacked already Chechnya, Georgia, and Ukraine).
Responses