It is however acceptable to kill 20 enemy combatants to rescue a dignitary from a besieged embassy.
The phrase "The ends don't justify the means" is not hyperbole to discredit accomplishments, nor is it meant to remove the ends from the equation. It changes the equation to provide the necessity of weighing the ends against the methods rather than measuring the ends independent of the context used to accomplish them.
What is even more interesting is the opposite. The ends not justifying the means is typically used for weighing the actions necessary for a favorable outcome. If looked at from the opposite perspective, do the means justify the ends, it presents a more difficult scenario. If X people die, but only appropriate means were used (and others would have saved X people), should those that chose the appropriate actions be held responsible for the failure to provide a favorable outcome? Or should they be heralded for making the difficult decisions to only use morally acceptable practices?
Even if the dignitary was Von Ribbentrop?
http://en.wikipedia.org/wiki/Joachim_von_Ribbentrop
Semi-deontological ethical rules suffer the same problems as deontological ethical rules.
There is a convention to these things - one doesn't assume that the dead school children were carriers of an incurable virus and that only their death prevented a deadly pandemic etc.
As I am sure you recognize, a patriotic motivation does not make an action right - even if your assumption that the rescuers and rescued share political affiliation might often lead one to assume your holding such a belief.
I.e. stealing qua stealing is always wrong, but it is right to steal to feed a starving family, if stealing is necessary. However, stealing is still wrong.
This slips into what I called "semi-deontological" ethics which has the same issues as ontological ethics, i.e. that it is possible to provide a counter example for any generic ethical rule. Until you get down to an actual example one may invoke Nazi's, fatal pandemics, or lawyers tied to railroad tracks.