The First Order by Jeff Abbott
In The First Order by Jeff Abbott, his protagonist, Sam Capra, a retired CIA agent is in hot pursuit … of his brother who he discovers wasn’t murdered as everyone believed. Instead, he’s been recruited for an assassination, on American soil, of one of the world leaders coming to the U.S. for an important summit meeting.
Sam is part of the Round Table that owns 30 bars across the world, but of course, the Round Table is a little more than you might suspect. This is Abbott’s 5th book in the Sam Capra series.
As always, I suggest starting with the first book in the series, Adrenaline.