In Israel the average tax that most pay is very high. As is known publicly, a large amount (more than 10% of the yearly budget) goes to the Bituach Leumi, which gives "charity" (in it’s own way). If I give 40% of my income in taxes, and the taxes I pay go at least 10% to charity, can this be counted as givin charity also? (I’m not trying to reconcile bills with G--d, G--d forbid. Only the Alachich point of view interests me).
I have seen poskim that say that no tax, including bituach le'umi, counts as maaser, but others disagree. Since there is an opinion that maaser is a custom and not a halachic obligation, one can be lenient. One who is in financial distress does not have to be strict concerning the various opinions in regards to maaser.