What's purpose of terrorism? Why Nations (Not only Islamic) employ it?
One of the more obvious reasons is to weaken nation internally before military conquest.
Another reason is to put pressure to weaken alliances, to make military forces retreat, as society grows fearful of possible invasion.
But there are more insidious conquest methods, without open wars.
First a Nation builds support, bribing - in one way or another, not neccessarily with money - certain groups, often intelligence & arts, or other influential people - including politicians.
Then terrorism destabilizes nation, media & propaganda attacks government, economy is attacked as well - making people suffer living with little money, banditry & crime run freely, government & police being rendered ineffective.
Groups of invading nation's influence get economic & other support, growing stronger - while their opposition is weakened by attacks on many fronts.
After years of being in such condition society has enough, is more ready to accept influence of invading nation, seeing them as more effective in restoring economy, averting crises & dealing with crime.
Sooner or later political votes are gained, and invading nation's influence grows enough to be a deciding faction in invaded nation's politics.
'Military support' arrives, police is trained ... order restored - but now government supports other nation, the one who succeeded in the covert invasion.
What if more than one nation is engaged in such covert warfare?
There's risk of nation sending troops earlier to 'restore order in society', risking an influence - conflict still, this time on military level.
Most of people are not aware that invaders who bring 'riches' brought them misery earlier.
