On the contrary, the spies thought that Eretz Yisrael could only be conquered by having a superior military (they probably favored a policy of focusing national spending on the military and taking people away from learning Torah to play soldier). Yehoshua trusted that Ha-Shem would hand over Eretz Yisrael to us with minimal effort on our part – no need to replace Torah and Mitsvos with military training. The spies lacked faith that Ha-SHem would deliver Eretz Yisrael to us in spite of military inability to do so by force.
Of course, the zionists aren’t so dumb. They know that Ha-Shem never told to conquer Eretz Yisrael from the Yishmaelim, and by many shitahs told us not to start the war and seize the government from the goyim, and since the zionist war isn’t a mitsvah they can expect no help from Ha-Shem, and are forced to rely on their own efforts.