Printed from http://tektonics.org/2pt3.php
The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance.
Arminian view: The words "any" and "all" must be taken seriously here. God desires all people to repent and to be saved.
Calvinist view: In context the "all" and "any" clearly means "all the elect" and "any of the elect." Peter's letter is addressed to believers and he speaks of God being longsuffering to us.
As with limited atonement(link 1 below), the controversy here is a tempest in a teapot. No Arminian, in spite of 2 Peter 3:9, thinks - even under their interpretation - that all men will repent and be saved anyway.
In our view the Calvinist is closer to the truth here, although as noted in the second link below, we define the elect in terms of primary causality: God chose this world to create instead of others, thereby essentially and primarily determining the "elect." And practically speaking, only these elect will be saved.
Therefore, in practical outworking, even if the Arminian interpretation is correct, practically speaking, what the Calvinist view understands is what will happen. The standard defense of two wills in God (a "will of sign" and a "will of good pleasure") is logically necessary if we are not to descend into the error of open theism.