[samus]

Depends on the country. Some countries have (similar to the US or Germany) just suspended the draft. Undoing this is not tricky at all.

Some countries (like Austria) draft their citizen and reserve the option to mobilize them in case of crisis. In Switzerland, every draftee remains part of the armed forces up to retirement and participates in yearly exercises.

Even if you don't get drafted, you might want to be able to protect your loved ones or simply be able to flee to safer areas. During a war, enemy soldiers are not the only threat. Societal collapse in the face of supply shortages or the frontlines closing in will make many people desperate and willing to take advantage of the situation.

Some countries let their citizens keep weapons. Sure, they won't be able to prevail in open battle against a professional army, but they might be able to wage asymmetric warfare. There is always the option of yielding to the attacker, but there are clear risks to that as well!