Jonni: Women have been able to enter the Finnish military since 1995 and attend military service in the same units as men and no major problems have been reported. I don't know what kind of rules there are for real combat situations.
Back when I was in Israel, there was this group of people that looked like small teenage boys and girls in a school trip. What caught my attention thought was that they were all carrying assault rifles.
They were all Israeli conscripts, and I would be quite surprised if half of them, especially the girls, could carry a gorilla weighting 7500 Swedish lods. But I bet they could shoot one with their assault rifles, though.
EDIT: I guess such strict physical limitations may exist mainly for paid armies, not in countries with compulsory service, like Finland and Israel.
That said, I agree with StinginVelvet that if there are physical requirements, they shouldn't depend on your sex. After all, there are smaller and weaker men too, so why should the same requirements apply to them either? Just because they have eggs and beans between their legs?