Earlier quoted context omitted.
> Conscription is slavery I abhor hyperbole. Slavery is the legal ownership of one person over another person and their progeny. Since they are property, slaves have absolutely no rights or any access to the legal system. You commanding officer cannot rape or kill you with impunity. He/She cannot force you to do fight with another conscript to the death. Conscripts also get paid, while slaves do not and are well fed…
There are multiple degrees of slavery. Eg. The Roman emperor Antoninus Pius forbade the killing of slaves without good reason, but they were still slaves. Slave does not have to mean literally zero rights.
I'd rather say that the word "slavery" has been used for certain forms of involuntary servitude with often many common characteristics. (Worker has no rights to leave, no other political and social rights of the free citizen such as right to vote if it exists, and for all intents and purposes is considered a property of their owner.) Usually it has been distinctive cultural and often also a legal institution, separate from other duties and forms of involuntary work.
This form of is generally agreed to be an evil thing (actually outright irredeemable horror in the US context that often dominates English-language boards such as this), so of course everybody likes to call any form of involuntary work they don't like slavery.
The topic of ancient Greece and Rome have already been raised, the revolutionary France likewise. (I think it's still notable to reiterate that conscription has been prominently around with these both ur-examples of modern Western concept of citizenship.)
However, let us have a more modern example: consider hypothetical case where prisoner serving a term is required to clean up their room once per week. Out of blue this sounds reasonable. Is this slavery? After all, the prison administration could hire a professional cleaner to do it.
As a slightly more realistic example, the Western concept of prison has often included working as a form of rehabilitation right from the beginning. Sometimes the "rehabilitation" part has been genuine, sometimes not; sometimes the work has been simply a meaningless punishment: sometimes goods are produced and sold; sometimes the prisoner receives a token pay, sometimes not.
It's easy to imagine a problematic version where calling that kind of working "slavery" does not seem misplaced, but it is also possible to imagine scenarios where it does. And in any case, one is drawing a comparison to a more ancient institution.
In some regards there are similarities, but on the other hand, it's also misses some critical points and is at best a very uncharitable choice of word.
Same goes for conscription, especially in a liberal modern democracy where the draft is fairly egalitarian (contrast against the quite arbitrary press gang method of the British Navy of the wooden ships and iron men age), is temporary, citizens generally are allowed to emigrate out of the country during peacetime, can vote in any elections that happen when they are serving, and the work they perform is fairly unusual and exceptional service (compared to regular peacetime job) for the society in an exceptional situation. Would a compulsory EMT training for everybody and then a requirement to use those skills if possible in a sudden situation that warrants their use also be slavery?