Theft is about more than just taking by force. If you steal a laptop and the police come and confiscate it back off you, then they are taking it by force, but it is not theft, because you had no legal claim on the laptop and someone else did. If the bailiffs come to your house and take your tv, they are using force, but again, by taking out the loan, you signed away your legal claim on your property, so it is not the same as theft.

The government makes the laws and the laws say you have to pay tax. So according to the law, the government has a legal claim on your money, so it is not theft to take it by force.

Tax is only theft if you can argue that there is some law that supersedes the government's law that they can raise taxes.