More military interventions with more refugees arriving at European borders?
There is basically no real threat to European countries atm. Russia is heckling a bit in Ukraine. Supplying Kalashnikovs to separatists and such. But in general, Russia is retreating. With Montenegro joining NATO and things going bad in Syria, Russia is losing access to the Mediterranean sea. And they run out of money quickly!
If things go wrong, special forces (a few hundred men) and French atomic missiles pose enough of a threat for rogue dictators. The large countries can't afford a war, because economic ties are too strong.
Military spending in Europe is exactly where it needs to be. Low. Humanitarian help throughout the world and keeping the inner stability of society (social security, health-care, retirement, ...) gives a lot more bang for the buck. (pun intended)