We escalate everything that we can. We believe that we are the police force of the world, but we don't always think ahead. There are a lot of things going on in the world, and while there are sometimes that we should get involved, many other times we need to keep our noses out of it.
The crisis in Ukraine is beyond anyone's control at this point. The nation itself is divided, and Putin has very little regard for the opinions of the rest of the world. Neither Russia nor the US is in a position to fight an all-out war, and neither has clear advantage over the other. This threat display on the part of the US is just that: a display.
No, the US is not escalating the crisis in the Ukraine, because Russia is the aggressor, rather than the United States. The USSR broke up in the 1990s. They decided that the Ukraine would be independent. Now, Russia wants to go back on that deal and take Ukraine back over. They are the ones at fault in this situation.
No, the US is not escalating the conflict in Ukraine by sending B2 bombers to Europe. The US has made its position clear via statements and the imposition of sanctions on Ukraine. All the aggression to date has originated from Russia. Continuing to support the Europe-leaning factions in Ukraine by providing resources is well within the conflict's current bounds.