I will answer your question with a question. If you rent a house are you contributing to the landlord's alcohol problem if he uses the rent money to buy liquor? Would you be justified in refusing to pay rent in order to keep from supporting his use of alcohol?

Same goes with the taxes, citizens are obligated to pay the taxes of the country they live in, it is our rent for the services provided by the country, the individual has no direct responsibility over what is done with the money.

We have sevearl choices, protest against the use of the taxes in a peacefull manner, but pay the taxes that are owed. Protest the war effort, in a peacefull manner. Be public about your dissatisfaction over what the tax money is used for, but pay them.