Support the Troops?

Okay... it's been several months since the War in Iraq officially ended (though no one seems to have told the "enemy"). And I think it's finally okay for me to ask this question:

What exactly does it mean when people say "I support the troops?"

I mean, I hope they don't get killed or wounded. I hope they come back home safely. I've sent care packages to them. I hope their families are well-taken care of. I let people know when the government isn't doing what it should be doing to support them, such as our president trying to reduce their hazardous duty pay or removing the benefits that families of soldiers in hazardous duty get. Is that what it means to support the troops?

Because I see a lot of people driving around with their "Support the Troops" signs and American flags on their cars, and I wonder - what exactly are THEY doing to support the troops?

It seems to me it's a lot of backlash from the Vietnam era, where you heard the stories about soldiers' poor treatment upon coming home. I can understand making note that the war itself isn't the troops' fault. It's the government's fault. And taking frustrations out on the soldiers doing the fighting is the wrong and immoral way to go. Reminding folks of that isn't a bad thing.

But is that what's happening here?