well think what would happen to ISIS if the drone count got increased 500% and NATO mobilised and invaded any and every location ISIS have claimed?
do you think that could have a impact? or do you need to time to think about it?
To be honest, i think something similar to first scenario will happen.
The creation of fear atmosphere is quite similar to post 9/11 USA. My carefree and mostly laid back European friends were talking about how they should wage war in wherever ISIS spreads and refugees should be sent back because they are all terrorists.
Some drastic measures will be taken and these will be okay because they will be for the greater good, safety of European people. Most part of the world counts West European and American lives above others esp. the ones in mainly conflicted countries like in Middle East and Africa (inb4 some European says "middle eastern media portrays their death more because those incidents are relevant to them" i bet none of you can utter a single Middle Eastern newspaper).
Anyway this interference will cause deaths of many and Western people will give their public nod until it is too late. Like how the opinions of current Americans and Americans right after 9/11 have major differences. Unlike before there are abundance of people who think war was unjust, but what does it change ? Nothing.