In Gurps, how powerful do you need to fight a tank?

[Lovewyrm]

Chuck boulders at it until the tank crew gives up.

Edit: Or use your super powers to relocate people before the tanks arrive at the destination.
What's the point of punching a tank? You think they'll call off the war efforts over that?

(This feels like some cartoony stuff to me and I'm not usually a fan of that, especially when it's for 'war' stuff.)