This is a really good summation of what investors are thinking about right now, from Dan Greenhaus (@danBTIG) of BTIG:
Our conversations this past week revealed client's sense of bifurcation. On the one hand, Friday's payroll report and strong ISM non-manufacturing index validate the strong U.S. thesis (first chart below, terrifically strong period for private sector job growth). However, weak data out of Europe, Japan and China continue to give clients headaches. Ultimately, most agree a strong U.S. is considerably more important than a weak [insert some other economy] but as we enter earnings season, the overseas weakness is one of two areas we're on the lookout for in terms of disrupting the reporting season (the other is of course the strong dollar).
There's no doubt about it, the US is leading the way right now in terms of the world economy.
We're seeing much stronger growth than Europe, and both Japan and China (and much of the emerging world) are struggling. This is fundamentally why the dollar is so strong, because the Fed is getting closer to existing ultra-loose monetary policy, while the rest of the world is nowhere clear to that.