I don't accept that.
Even if it was true that there is no judicial process that would work, that wouldn't be perverted over time, we still control the law through elected officials. (Ok maybe not in the case of international law but even then as a sovereign nation we either agree to abide by the international law or we don't.)
As long as the election process is not corrupt, we should endeavor to either perfect the judicial process or make the law reflect the enforcement reality.
In other words, if the law needs to read captured pirates are executable by maritime captains, because no judicial or trial process will work for them. Then that's what the law needs to say.
I can't applaud a Russian captain killing captured pirates, even though they almost certainly deserved it, when it means ignoring the rule of law. That undermines the rule of all law.
Then we’re going to have disagree.
The “rule of law” is a means to an end and is failing to serve that end. Further, there is no indication that it will be turned to meet that end; quite the opposite, in fact.
That means other methods have to be used achieve the necessary ends. As far as I’m concerned, in this particular instance, the Russkis “done good.”