The young don't want to fight, never have throughout history really. If societal peer group pressure can't incite you to violence, we just mandate them to for "the common good".
Should have a UN resolution to ban conscription for war. Fair enough I reckon if people are not willing, should not be forced. Kinda falls in the individual bodily autonomy rights area as other recent issues have.
Russia is doing the same, calling up former national service types that have no desire for war.
Russia isn't just calling up all young reserves - age for enlisted goes to 45 and age of officers to 55. Russian reserves aren't like American reservists who practice a couple times a month and a few weeks each year. They are just men who, at some point, were in the military.
Airline tickets out of Russia, if you can get one, are exorbitantly priced, and the road to Georgia is backed up with cars for miles with Russians fleeing (videos look like refugees fleeing war).