1) Women can have children, and after a major war a large section of the population may be killed, and its better to have more women than men, since you can repopulate faster.

2) Women take over a large share of industrial labor during wartime. This was a mistake the Germans made in WW2, because they were so mystified by Nazism. But in the US, women basically took over all the manufacturing jobs that men left when they went to war, and it helped shore up the industrial base and, in the end, helped lead to an allied victory.

In a place like Israel, there are so few people that it doesn't make a massive difference. If half the men get taken out, its not like the 2-3 million remaining women are going to be able or even want to "repopulate" so rapidly (not to mention that Israel has an interesting setup where a small section of the women make up the majority of the births--the ultra-orthodox--and the majority probably aren't having kids anyway).