Who should be exempt from serving in the army?

Now that the Supreme Court has canceled the Tal Law and done away with army exemptions (at least for the moment), it is important to understand  who if anyone should get an exemption. Here is a quote from an article of R' Aharon Lichtenstein on exemptions for yeshiva students (Tradition, Fall 1985) who presents a very compelling argument against draft exemptions:

Finally, even if we grant that the Rambam's statement does imply a categorical dispensation in purely halachic terms, it remains of little practical significance. We have yet to examine just to whom it applies. A levi [sic] is defined genealogically. Those who are equated with him, however, literally or symbolically, are defined by spiritual qualities; and for these the Rambam sets a very high standard indeed. He present an idealized portrait of a selfless, atemporal, almost ethereal person - one whose spirit and intelligence have led him to divest himself of all worldly concerns and who has devoted himself "to stand before God, to serve Him, to worship Him, to know God; and he walks aright as the Lord has made him and he has cast off from his neck the yoke of the many considerations which men have sought." To how large a segment of the Torah community - or, a fortiori, of any community - does this lofty typology apply? To two percent? Five Percent? Can anyone... confront a mirror and tell himself that he ought not to go to the army because he is kodesh kodashim, sanctum sanctorum, in the Rambam's terms? Can anyone with even a touch of vanity or a concern for kavod contend this? Lest I be misunderstood, let me state clearly that I have no quarrel with economic aspiration or with normal human foibles per se. again, least of all do I wish to single out b'nei yeshivot for undeserved moral censure. I do feel, however, that those who would single themselves out for saintliness should examine their credentials by the proper standard

In essence, RAL's point is that requires a tremendous amount of hubris for a person to say that my learning is so important that I don't need to go to the army and fight, especially when in many other areas the person doesn't show such great faith (as RAL describes). It is very nice for a person to say that they are joining Shevet Levi, but who says that they were accepted?

This is even more relevant today because very few 18 year olds are really choosing to be in Shevet Levi. When the exemption started most people served in the army and therefore to get an exemption meant making a conscious decision to dedicate yourself to learning Torah. Today it is just the opposite. All Charedim in Israel are simply assumed to be learning and there is tremendous societal pressure to do so. Anyone who chooses to not learn is an outcast, off the derech and looked down upon.  Therefore to say today that all of these 18 year olds are joining shevet levi is simply not true. They are simply doing what society expects of them.

There is 1 more very important point. There already is a system where Yeshiva students go to the army it is called Hesder and there the students commit to a 5 year program where they spend a year and a half in the army and 3 and a half years in the Yeshiva.

IMHO such a system should be instituted for the Charedi world as well. I would propose the following:
1. 3 years learning in Yeshiva (17-20) before the army
2. At the age of 20 enter the army for a year and a half (in an appropriate setting, no women, kashrus, etc.)
3. At the age of 21.5 they are free  to do what they want, go back to yeshiva, work, whatever.
4. A small percentage of students in any Yeshiva would be granted a permanent exemption. This would be reserved for those thought to be the generation of Torah leaders (if after 3 years in a Yeshiva you can;t identify these people then you have a real problem).

I don't see how a system like this would destroy the Torah world. Bottom line, it is a year and a half in teh army and then back to the Yeshiva. Devoting a year and a half to defending the country might even have positive effects in terms of maturity, growth etc. and after the year and a half service they could sit and learn for as long as they want with no one bothering them.

IMHO the real reason that the Charedi leadership is against plans like this is because a plan like this means that at the age of 21.5 - 22 the guys are free to do whatever they want. They can go to work, go to school whatever, and the Roshei Yeshiva are afraid that without anything hanging over their heads the Yeshivas will empty out. To that I say, if you have to force people at the age of 22 to stay and learn then it is better that they should go out and get a job.