In The Princess Bride, after hearing Vizzini say “Inconceivable!” once too many times, Inigo Montoya tells him, “You keep using that word. I do not think it means what you think it means.”

Similarly, Republicans keep talking about “benchmarks” for Iraq. I don’t think it means what they think it means.

President Bush and congressional Democrats don’t agree about much when it comes to the Iraq war, but one of the areas where they disagree the least is the need to measure the Baghdad government’s progress.

That makes the issue ripe for negotiation in an evolving veto struggle over the war, even though the administration and its critics are fiercely at odds when it comes to how — and whether — to enforce these so-called benchmarks for self-defense and democracy in Iraq’s post-Saddam Hussein era.

No matter how encouraging this may sound, war supporters’ use of the word “benchmark” is not consistent with any kind of meaningful definition of the word.

Indeed, this week, Tony Snow was asked why the administration wouldn’t at least consider “political benchmarks with consequences, given that there has been so little, if any, progress politically from the Iraqis.” Snow rejected the notion out of hand: “[I]f you set a political benchmark with penalties, that would imply that you have a timetable, that you have certain deadlines.” The NYT reported today, “Several Republican leaders said Tuesday that they were likely to support such benchmarks, and White House aides said Tuesday that Mr. Bush, who has supported goals and benchmarks for the Iraqi government, might back such a measure — but only if the benchmarks are nonbinding.”

What we’re left with is the exact same notion Republicans have been using for over a year: “benchmarks” that are little more than suggestions.