As long as the US dollar is the reserve currency of the world, the US fundamentally exports deflation. When and if the dollar demand falls enough, inflation would become rampant.

So yes, we're preventing deflation now. And that will work - until it doesn't. In present state, and assuming no CB changes in buying, the US can print just about as much money as it likes. Problem is, when other CBs stop buying, the inflation hits home like Weimar.