This past week Archbishop Silvano Tomasi, the Vatican's top diplomat at the United Nations said this group of Jihadists were committing "genocide" and that they needed to be stopped. He went on to say that a coordinated, well thought out coalition first needs to do everything possible to achieve a diplomatic settlement - without violence, but that if that turns out to be impossible, the use of force will be necessary.
The Church has stated, officially, that if the world (including itself) does nothing while this genocide continues, many years from now our children and grandchildren will wonder why we sat by and did nothing.
Endorsing violent action against ISIS, or any other group, is not something the Church takes lightly. However it's belief system is that evil exists and the good need to combat evil... and it views ISIS as a great evil.