Unsettled Irish cannot leave: hard to evade conscription! (8,7)
I believe the answer is:
national service
'conscription' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for national service that I've seen before include "Period of peacetime conscription" , "Compulsory period in the forces" , "What conscripts had to do" , "Period of compulsory conscription" , "In a period with the military" .)