After going through a bit of soft phase at the beginning of 2018, the U.S. dollar has gained quite a bit of value opposite the Euro. Most recently, US$1 was buying 0.9 Euros. This trend is mirrored with many other global currencies and the currencies of U.S. major trade partners.
The strength of the dollar has advantages (namely cheaper imports) but there have been many critical of the strong dollar, including U.S. President Donald Trump. Trump said repeatedly that he would support a FED policy weakening the dollar, because it would aid U.S. companies doing business abroad. Currently, businesses who have to convert foreign earnings back into dollars are getting out less and are therefore potentially less competitive.
Trump has blamed federal interest rates, which are currently higher in the U.S. but remain at zero in Europe, for the strengthening of the dollar. The unequal rates are in fact a major draw for investors to move assets to the U.S. As more people buy (in) dollars, the demand for the currency goes up, strengthening it. China’s Central Bank, for example, has been accused of keeping its currency artificially low to be very competitive in the global marketplace.