Unless the salary they pay you is sufficient to induce you to join the army regardless of other penalties, it's forced labor. You are forced to perform labor you would not otherwise perform.
Just to back up my version slightly, here are the first two definitions when you Google "define: forced labor":
"[...] a generic or collective term for those work relations, especially in modern or early modern history, in which people are employed against their will by the threat of destitution, detention, violence (including death), or other extreme hardship to themselves, or to members of their families"
"Work which one is compelled to perform against one's will, especially in a condition of involuntary servitude as a prisoner or slave"
[Emphasis mine in both cases.]
Neither of these really fit when talking about Israel's army conscription. There are some societal problems with not serving in the army (people look down on not serving, and sometimes people who haven't served have a harder time finding jobs,) but there's nothing approaching the level of what's talked about in those definitions I quoted.
Libertarianism (for example) argues for a particular zero, communism for a different one.
Different governments disagree on where it is appropriate to set this zero. Israel has chosen its position, and although somewhat unfortunate for Israelis, I don't believe this is a terrible choice.
That's not exactly true. Conscription is necessary (consider that Israel is a tiny country, but has a lot of enemies.) The symbolism is important too, but it's not the root cause, it's just a nice added benefit (there are a lot of other benefits to this, by the way.)
That said, I don't think you can consider it forced labor. Soldiers are paid a salary, which is tiny, but they get a large amount of money at the end of their service. Plus, they theoretically get every expense paid for by the army (theoretical because most soldiers do go home to their family, either every day or every few weekends.) Soldiers who do have a hard time economically (no family, or a family with a hard time supporting them) get a lot of other benefits, which range from higher salaries, paid-for living quarters, and having lots of time off to go work at a second job and make more money, if they need it.