Students who fall behind in their school work will never be able to get jobs and will end up living with their parents forever. the flawed logic in this statement is an example of

This should be a slippery slope logical fallacy.

That's when you start with a thing and swiftly move on to the consequences that may come from that thing and are usually negative. Here you have the slippery slope that if you don't do your homework, you are bound to fail and end up being a failure while it is not so in reality.

Because the vietnam war was fought in an especially brutal and untraditional way