I think security spending is bound to increase in the region due to unstable geopolitical relationships.
As a student of history, I see Brexit as a sign of storms on the horizon. The European Union project has proven a major success at its original goal: Preventing war.
Foundations first arose in the wake of WWII when Europe was still in ruins, as a way to increase ties between factions and countries who'd been murdering each other for centuries. War of the Roses and The Hundred Years War took a backseat to NATO vs Warsaw Pact.
The basic premise of the union was the more member interaction, the less they would fight. And you know what? They were right. This is the longest peaceful period in European history.
There is a lot to be said for other cultural dynamics changing in Europe, but taking a narrow view of just Brexit makes me wonder if a dissolution on a bigger scale is in the future.