Security tax

Hello Rabbi,
What do you think about collecting a security tax from everyone who does not serve in the IDF, thereby financing expensive defense systems and hiring a private army for defense missions?
Ostensibly, such a tax would solve the problems that the Haredim have with the "conscription decree," because: (a) there is no danger to spirituality/Haredi women; (b) it is not a punishment like the various sanctions, but only funding defense needs instead of actual service; (c) it can be imposed equally on everyone who does not conscript, and thus there is no claim of intentional discrimination against Haredim.
I suppose you'll argue that the evil Haredim will avoid this too, etc., but if it were shown that they would agree to such a solution – do you think it's a good idea?