Socialists generally have an internationalist bent and believe in no national borders. Not to mention that socialists of all stripes work together, whether atheistic, “humanist” or Islamic.
I would say that there is a dichotomy between fighting for the integrity of Israel’s borders and fighting to break them down. Which do the socialist veterans believe in? and did they do the defense of borders thing merely on orders, in order to avoid any kind of dishonorable discharge and thus availing of care from the state? (Rotten question to ask, I know, but one never knows another’s heart.)
Israelis are nationalists, believing that Israel is the last and ultimate refuge for Jews - and they have and will fight to defend it. Israel is undeniably also a welfare state, and therefore socialist.