If you really want to be nerdy about it, filing your taxes constitutes a contract to pay them. If you are financially capable of honoring the contract, but fail to do so, jackbooted thugs will drive you around in a partyvan & put you in jail. Gratis.
Is that not "enforcing the collection of taxes" ?
It is, but the government itself was not responsible for that force so no laws need to be on the books. That's the ticket! Shirking responsibility since 1776. This is how the US gets around a lot of shit like this: third-party van parties.