Is the USA one of the only countries where men have to pay both alimony and child support? How do other countries work?

[Archibault]

I was reading and it seems in Quebec men don't have to pay alimony. It might be the same in other countries as well.

[Yohan]

Laws are different from country to country.

UK is at least as bad as USA.
Here in Japan child support cannot be enforced, however if you find no child support agreement with your ex-wife, she can refuse visitation rights in return. Alimony in Japan is very rare, usually only in case of divorce of very old people, where the man has a high company retirement allowance and the wife has nothing, and only if the marriage was existing for many years.

In Continental Europe it is also possible that a man could be forced to pay both, alimony and child support, but it is clearly much better regulated, for how long and how much, not like in USA or UK.

Usually such payments are calculated monthly in percentages depending on your income and the income of the ex-wife.
Alimony in general is only for a few years especially in case of small children.
Long-term alimony is rare, for special circumstances only, like if the ex-wife is handicapped after an accident or in elderly care home or something like that.

There is also a basic existence minimum, which cannot be taken away from your income under any circumstances, so you will never end up living in a car or being homeless like in USA. I am not sure, but in my native country in EU the minimum might be something like Euro 850,- or so, maybe USD 1.100,- net, which cannot be touched.
You will also remain within the national insurance, therefore medical bills will not bankrupt you.