ROME — For Europe, the first move was easy. Officials swiftly announced plans to strike back with retaliatory measures against President Trump’s tariffs on steel and aluminum while vowing a legal challenge.

The next move is more complicated and uncertain. Though European leaders project unified resolve in confronting what they portray as American bullying that breaches the rules of global trade, they have not proved adept at setting aside national differences in pursuit of common aims.

And Europe at the moment appears especially divided and internally conflicted.

Britain is headed for the exits. A potentially destabilizing, populist government just assumed power in Italy. Spain unexpectedly changed leaders as well, while Hungary and Poland are testing the values of the European Union with policies anathema to democracy. In addition, European economic growth appears to be slowing, with factory orders down in Germany.

In European corridors of power, anger at the Trump administration is intense — not just because of the tariffs, but also because of the American decision to revoke support for the Iran denuclearization deal. Yet given the difficulties Europe confronts in orchestrating any policy and given competing economic interests across the 28-nation bloc, Europe is in a compromised position as it squares off with a bellicose American president.