“Isn’t it wiser to temporarily part ways with the Trump administration?”

Trump's withdrawal from the Iran nuclear accord confronts the other parties with decisions that will do damage no matter what is decided.  If, as they have said, the other parties--France, Germany, UK. the European Union, Russia, and China--are determined to make the pact work, they will come into direct conflict with U.S. sanctions.  The U.S. will place sanctions on any company that does business with Iran.  If those companies do as the U.S. wishes, they will lose the investments they made in Iran.  However, if they wish to honor their commitments, their governments will need to intervene.  Because America is a big factor in the economies of its allies, the foreign governments are very cautious about possibly jeopardizing the trade arrangements.  The resentment against American dominance has always existed,  but it has grown into a factor that could motivate countries to reduce their reliance on the  U.S.as a partner.  China and Russia are willing and ready to take up the leadership role that Trump has stepped away from.   European countries are  reassessing the value of the U.S. as an ally. 

European countries are openly recommending that they follow the pattern of Mexico in dealing with the U.S.  Mexico has left a line of communication open but has canceled a number of meetings with U.S. officials.  While the NAFTA talks drag on, Mexico has made arrangements to purchase agricultural goods from Brazil and Argentina that it once got from the U.S.  European officials think their own countries could be best served by realigning their international relationships to greatly reduce the role America plays in their politics and their economies.  That is the reasoning behind a senior European Union adviser  suggesting, “Isn’t it wiser to temporarily part ways with the Trump administration?”  

The U.S. has lost much trust and respect throughout the world.  In the media,  his groundless assertions displace the actual facts about how other countries see us,  and how strongly motivated they are to create alliances and relationships that don't include us.

America is not regarded as a major player in essential world affairs.  That is its choice.