The Catholic Church defended the selling of indulgences because they needed the money to fund their projects. One of these projects was the reconstruction of St. Peter's Basilica in Rome.
Non violent protests that worked just as much as it failed.
At the turn of the 20th Century, the United States was on the rise.
Spain was the last remaining European power in the Western Hemisphere and the US was eager to prove it was top dog.
So, it went to war to kick Spain out of the Western Hemisphere.
It was very much looking for an excuse to fight Spain.