Many Pacifists argue that it is morally wrong to finance war by paying taxes. Because of this some have resorted to war tax resistance, either by refusing to pay tax at all, or by withholding the percentage of their tax, estimated to be spent on the armed services.

Of course this form of non-violent civil disobedience is illegal, and anyone who refuses to pay tax can incur significant penalties.

The Bible verses quoted at the top of this page say it all!
(But we will say a bit more anyway!)

When Jesus said "Give to Caesar what is Caesar's" (Matt 22:21) He was answering a simple direct question from Pharisees who were seeking to find an occasion against Him. They had asked "Is it lawful to pay taxes to Caesar, or not?" (Matt 22:17)

Those Jews to whom Jesus spoke, were living in a land under military rule from Rome. Israel was occupied by Caesar's army! And there was no doubt at all, that some portion of the taxes that He told them to pay, was a "war tax"!

"Let every person be subject to the governing authorities .....not only to avoid God's wrath, but also for the sake of conscience. For the same reason you also pay taxes, for the authorities are ministers of God, attending to this very thing. Pay all of them their dues, taxes to whom taxes are due, revenue to whom revenue is due, respect to whom respect is due, honor to whom honor is due." (Romans 13:1,5-7)

"Be subject for the Lord's sake, to every human institution" (2 Peter 2:13)

"Let none of you suffer as ..... a wrong doer" (1 Peter 4:15)