Depends what you call Front Line because since WW1 there has not been a lot of front - most soldiers from WW1 onwards were killed by someone who never saw them and most male soldiers in WW1 were not as fit as women today. Women lead more dangerous lives than men in most countries. What I find strange is for example in certain places like France, the men are short and thin - British, American, Nordic women would mostly be taller and stronger, and yet the men are considered stronger because...they are male. Imo women in history have fought in every single battle that men have lost because they and their children are considered the spoils. Hitler ordered machine gun training to women when he realised Germany would surrender in WW2. There are examples if you google it, in WW1 there was a Polish woman who fought at the front as a soldier and there was an English nurse working in the Balkans who was left behind after an attack - she walked back to the Serbian lines and fought with them for the remainder of the war, becoming a major or something. She only died towards the end of the war during hand-to-hand combat - her opponent let off a hand grenade that killed them both.
BTW previous poster, many, many soldiers take paternity leave and some pull a fake sickey or simply quit. The number of men that come out harmed psychologically may point to the fact most men are not made for war either...the army has always been a route to take when one hasn't done well at school, not mentioning the royals or anything like that, at all. Also, today with the 'threat' of terrorism, the number of 'soldiers' being paid to do a bit of patrolling in the shopping centre vs any seeing any action is staggering...this is billions of pounds going to men purely because they are men.