Notice that I wrote *future* revenue. You can't unwind centuries of close cooperation and trade in a day, a month or even a year. But you can start a process that can't be undone once started. And Trump has done that.
Before, American companies were seen as friendly and even preferred trading partners. Now they are not. American products were in demand simply because they were American. Now they are not. The American tourist industry has also taken a massive hit.
Europeans (and Canadians) will no longer have American products, solutions and travel destinations as their first and default choice. However, the true ramafications of this won't be apparent until more time has passed.