I hate to crib Glenn Greenwald's blog again, but he responded to your argument in an update to the post I cited earlier:

Quote:
A couple of commenters have argued that there is a fourth option -- U.N. sanctions -- but sanctions are properly seen as a negotiating tool and thus a subset of option (2). Sanctions are intended to pressure a country into capitulating to an agreement on favorable terms. But whether they are viewed as a tool for negotiations or as an option unto themselves, they are scorned just the same by the anti-diplomacy crowd as a form of "appeasement." The argument that is advanced is that countries such as North Korea and Iran are so irrational, deceitful and evil that they can never be trusted to comply with the terms of any agreement -- whether the agreement is brought about by negotiations or sanctions. Only regime change, via military force, provides the necessary assurances.

Sounds about right to me.