The us has almost nothing to do with the terrorist threat. These are Muslim terrorists who are mad at the Russians.
FIFY. Muslims hate everyone. We could have the Olympics in Dubai and there would be a threat of terrorism. It's who they are. Muslims are at war with everyone, all over the globe.
The Osamist variety, the Islamists, certainly do. Both quotes are true.
Where the Osamists are concerned we share a common enemy with Russia, or any civilized power. To back out of going to an event because of a terrorist threat would send a terrible message of timidity. To insist on precautions and pre-emptive measures is reasonable. (Have a feeling Putin won't shirk from those anyway)
As for the Winter Olympics in general, not sure if it is the climate or timing, but it has always been over-shadowed by the `summer' Olympics, which for one reason another, when they open, seem the `real' Olympics to many to by the `who cares' remarks about the Winter.
Not sure why that is---perhaps because the ancient and also earlier phase of Olympics in the last century emphasized the warm weather sports in imagery and symbols.