I'll agree with the LBJ lying. In Bush's case, it's more complex. Our intelligence agencies grossly exaggerated the threat Saddam Hussen posed, but Iraq was a leading source of terrorism and terrorist training so they did pose a threat in that manner.
Of course, Clinton got us unnecessarily into Kosovo, so it's hardly the first time or last. There were the "Banana Wars" in Central America in the 20's and 30's we should never have gotten into. I could toss in US involvement in Asia from about 1870 to 1940 as another example, of our land grab to build the Panama Canal...
There's plenty of shitty examples to go around.