Can a modern state be run according to Halacha?

A year and a half ago the Bostoner Rebbe spoke at a news conference and said the following:

אני מפחד מהיום שיהיו 61 חברי כנסת, כי אני לא יודע איך ניתן לנהל מדינה עם האחריות של שמירת התורה. לדוגמה, לסגור את שדה התעופה בשבת, בעולם המודרני אני לא יודע איך אפשר לעשות את זה". ובכנות הוסיף ש"ברוך השם שלא באים לשאול אותי שאלות כאלה".

I am afraid of the day when we have 61 MKs because I don't know how you can run a state with the responsibilities of keeping the Torah. For example, shutting down the airport on Shabbos, in the modern world I don't see how you can do that. And in a moment of candour he added "Thank God that no one comes to ask me these types questions"

This raises a rather important question abut Torah Judaism. The Torah is supposed to be the the perfect blueprint for a society and yet the Bostoner Rebbe (and it's not just him, it's all of the Charedi leadership) doesn't have answers as to how to run a modern state al pi halacha. What does this say about the Torah and the society that the halacha requires? If the Torah was given by God for all times and places, then surely it should have answers for a modern society.  The problem is that the Torah deals with an agrarian society and the world has moved on.

Unfortunately, this is emblematic of the modern Charedi leadership,  don't deal with the modern world, rather withdraw from it. Don't engage with the world, rather have a Shabbos Goy (or non-religious Jew, or a Baal Teshuva) do the work for you.

It's very interesting that the Bostoner Rebbe pointed to closing the airport on Shabbos as the big problem that he has no answer for. Truthfully, that is the least of the problems. Power generation, police and army activity on Shabbos are much bigger problems. How do you balance security against chillu shabbos? Imagine if the police just ignored all non-pikuach nefesh issues on Shabbos, (robberies, rapes, car theft, etc.). How do you deal with industries (for example Intel's chip factories) which can't be shut down once a week? How would you create a workable justice system given the Torah's rules of evidence? Would Israel be like Saudia Arabia and have public lashings? The role of women? Slavery? The list goes on and on.

Just as problematic are economic issues that need to be dealt with. Modern economies are based on credit and interest, for example, every modern state sells government bonds which pay interest and the central bank sets the interest rates for lending. The consumer economy is very much driven by interst based lending (credit cards etc.) What about the prohibition of ריבית? What is the status of a company in Halacha? What would be the status of the government? The list goes on and on.

In truth, I agree with the Bostoner Rebbe, I don't see Torah answers for these questions however, we draw very different conclusions.