This an interesting subject.
The following article discusses a shift in policy fighting ISIS/ISIL by increasing military operations. They lost Qaduli. They said that before they were asking their soldiers to come home and fight and now that are asking them to stay put and create terror where they are. We may see more operations like the one in Brussels. They felt was are making progress.

Raid that killed an Islamic State leader marks a shift in U.S. strategy - LA Times