>By definition, none of the three instances were "pre-emptive". In each case a real danager existed. Here, there was none.

I we must have different definitions of "preemptive". From Dictionary.com
"Relating to or constituting a military strike made so as to gain the advantage when an enemy strike is believed to be imminent"
"Undertaken or initiated to deter or prevent an anticipated, usually unpleasant situation or occurrence"

Preemptive war has nothing to do with real or imagined danger, but instead attacking before, instead of after the danger comes to pass.

In Iraq: it was believed (falsely) that Iraq threatened someone (the US, the world, its neighbours) by its mere possesion of WMD's. Sounds preemptive.

In Grenada: The US feared that it was losing control of its sphere of influence in the western hemisphere and that the Soviets and Cubans might set up a military base to project their military power and politics into the region. So a threat existed, but before it was carried out, the US pre-emptively attacked Grenada. Do you not agree?

In Panama: America was set to lose control of the Panama Canal on Jan 1, 1990. To prevent the possible loss of the canal as a commerical and military sea route, the US Invaded (under the guise of protecting the freedom of Panamanians). The US preemptively attacked Panama, to prevent loss of use of the canal. Agree or not?

To been non premptive, the US would have waited for a Soviet military base to be developed and to would have had to wait until they loss their use of the canal.