While re-rating of US equities in last one year partially reflects the execution of corporate reforms, significant improvement in US domestic companies' competitiveness, on account of fiscal incentive, is arguably underway.
In the U.S., the Fed has to change (monetary policy) now that inflation is taking off.
Shale is not going to be such a bottomless production pit this year.
In the U.S., three or four rate hikes is just not enough at a time when the ECB has said more or less definitely they are going to be terminating QE (quantitative easing) in September and even beginning to talk about rate rises.