Besides factual inaccuracies, such as the indefensible simplification of the very diverse groups collectively referred to by many as the Contras, and disagreements, such as the second-to-last point, I do not believe the superimposition of deontological ethics onto foreign policy is an accurate gauge of what does and does not promote American interests.
I put it to you that the superimposition of deontological ethics onto anything and everything is, however, the entire point of deontological ethics.
True, but you justify so by calling things moral and immoral. Not hijacking the arguments of other value-based arguments. Making a deontological argument, for example, on the issue of "does this materially help me the most", is highly misleading.
Since of course, there are those that naturally dismiss any viewpoint incongruent with their own intellectually incestuous viewpoints as "trolling", let me outlay the basic jist of my argument.
The idea that Iran is a hostile enemy that we have to oppose on everything is ridiculous. Contrary to popular opinion, although many goals of the IRI clash with US interests, the primary goal of the Iranian government is not the destruction of the United States. To ignore areas where Iranian and American interests coincide is, I believe, a mistake. And unfortunately, extremely anti-Iran public sentiment at the time made it difficult for us to openly deal with the nation.
Obviously, the US didn't want to see either Iran or Iraq decisively winning the Iran-Iraq War. During the time when the arms sales happened, Iraq was definitely winning that war. It's not entirely a "bait and bleed" strategy, but a decisive Iraq victory would have possibly pushed Iran into the Soviet sphere of influence (Iran being at the time, hostile to both major powers). There's no real downsides towards selling weapons to someone fighting a war you don't want them to lose - even if you don't like them.
At the same time, the US really didn't want a pro-Soviet outpost in Central America for a myriad of reasons we can spend a long time going after. Now, Contra is just a term given to a huge variety of anti-Sandinista groups. They were extremely diverse. Anything from far-right paramilitaries to militant Amerindian rights groups nonplussed with the Sandinista government. Obviously, some of them would engage in human rights violations, but that's pretty standard fare in almost every civil war - just look at how the Libyan rebels we supported butchered Gaddafi.
Now, the Iran-Contra "scandal" irritates me because it's a perfect example of how the BS political football we play with foreign policy isn't good for anyone. Quite frankly, there are little to no foreign policy differences between Barack Obama and Mitt Romney. But the public expects both of them to campaign on foreign policy - as demonstrated by the useless, stupid, damaging foreign policy debate they'll have soon. The ideas that Obama killed Bin Laden (or that killing Bin Laden was useful), or that Obama killed our ambassador in Libya, are both stupid as hell.
Quite frankly, the only reason Iran-Contra was illegal was because of stupid Congressional meddling in our foreign policy. And stupid congressional meddling in our foreign policy can really trip us up - I think for example, we can both agree on foreign policy regarding Israel being an example.