It a shame that so many of the Zionist posters here are appealing to emotional arguments (PY – what would the soldiers say; LMA – divining that the good outweighs the bad; AOM – appealing to some national homeland idea). There are valid legal arguments that can be mounted for the Zionist cause (though I don’t agree with them, and those should be the focus of out halachik analysis.
For all those who say they are against the Zionist ideal in principle but conclude that once the State is here we might as well deal with it, please refer to R. S.R. Hirsch’s concept of “austritt.” I readily concede that this idea is open to reasonable disagreement, but according to R. Hirsch a Jew cannot support or condone the existence of un-Jewish institutions (i.e., institutions that do not purport to regulate their conduct by the law of the Torah). This is a very severe injunction because institutions have a way of legitimizing and perpetuating anti-Torah conduct in a way that individuals cannot.
Even after the establishment of the State, supporting, legitimizing, or condoning the institution (whether the government – as distinct from the politicians themselves; or the army – as distinct from the soldiers themselves) is problematic; it legitimizes the whole institution and what it stands for, as well as perpetuating the anti-Torah values of that system.
For me, the problem with the mishebayrach is in its precise language. Certainly Jews who are placed in dangerous situations – whether rightly or wrongly, deserve our special attention. However, we can differentiate between the soldiers themselves and the success of their mission – to perpetuate and protect the institution of the State. I would be content to pray fro their welfare, but not connect this prayer in anyway to the success of the institutional goals of the Israeli military.