The theory you present in that thread assumes that national security will forever be the main subject in Israeli politics. The problem is that long-term national security goals have lost some importance over time. To take an extreme example, do you think that in Holland the division between the big camps is also on themes of national security? And what about the US?

And a side remark: One benefit of democracy that you haven't acknowledged is reduced proneness for errors. Strangely enough, we are not only electing a prime-minister (the executive) but also a parliament (legislators). What is the purpose of these people? If 61 of them are smart politicians who form the coalition, why do we have to pay the salaries of the other 59 who do nothing but disturb them?
The reason is that these 59 are motivated like hell to find alternative ways to make the public better-off and point out errors of the government. This way, the system as a whole makes less mistakes than what a dictatorship would make.