IELTS Task 2 - Compulsory military service for all countries

I wrote this essay in a hurry. Please check it for me
Thank you :)

Many countries have compulsory military service for men after they leave school. It would be a good idea for all countries to adopt this system for men and possibly women. Do you agree or disagree with this statement?

A much debated issue of today's concern is whether all countries should apply the compulsory military service for men and even women. Many arguments have been put forward about this. However there is no room for doubt that the feasibility of this policy depends on many conditions of each nation. Accordingly, I am convinced that there are both merits and demerits that countries should consider when adopt this system.

On the plus side, military training will have the most effective on people from 18-25. It is clear that people in that age usually have better health than other ages, thus harsh exercises cannot suck out all of their strength and people can easily recover after doing hard works. Moreover, there is a fact that these people are youngsters and that this will be very good time for approaching knowledge. The training course will have the best influence on young people, therefore if they are called up to fight, these trainers would be well prepared to save either themselves or country.

For every plus there is a minus. For one thing, if people must do military service immediately after finishing education, the result of military training course will not have real effect. Country forces young people to do the obligation so they will do their jobs under the grudging attitude and do not devote their efforts to complete their missions. What is more, this seems to be unfair for one who intelligent enough to become doctor or scientist. This because youth is the most suitable period time that one can widen their horizons and that participating army is regarded as wasting talent of country. It is not only effect to the development of country but also destroy dream of a person.

When all is said and done, I hold the firm that the system that every countries want to apply have both advantages and disadvantage. Nevertheless these governments should adjust the policy to fit with their conditions for mutual benefits between government and population.

I can't get it. I have no idea what you want to say here, but I will suggest my own interpretation:
As a plus, military training will render to be most effective for people aged 18 to 25.
I like your style, you have good logic and ample evidences, but what you lack is thesis. In my view it's the most important, vital part of the essay, because it conveys your reasoning ability. So the topic asks very nice if you agree or disagree. You are floating in the middle, only touching the pros and cons of the described situation. You are supposed to get a position and defend it, I think. You can either be an exponent of military service, or deny its merits. Not both.

yep, thank you, I will try to rewrite it in different way

hi suyper,
here i would like to add that,question is very important.from one of my IELTS teacher i heard that it would be better if you give your opinion according to your question in your introduction paragraph.so do you agree or disagree the statement.if you are inbetween of these two then it will be better to write ''In some extant...'

thanks.