[the]

Here's a thread that I keep around for similar reasons. Comment #4 is entitled The Logic of Inquiry: Rhetorical Devices.

The first post of the same thread is "Propaganda Techniques".

Both are very useful refreshers.

[Sir Gawain]

From the link:

Least of Evils: This is a technique of acknowledging that the course of action being taken is perhaps undesirable but that any alternative would result in an outcome far worse. This technique is generally used to explain the need for sacrifices or to justify the seemingly harsh actions that displease the target audience or restrict personal liberties. Projecting blame on the enemy for the unpleasant or restrictive conditions is usually coupled with this technique.