Exactly. My opinion is that Russia should have dealt with him, if it needed to be done. It's another question why Russia hasn't, and there could be many reasons I suppose.
But I don't think there is ANY rationale that the USA arrests a Russian citizen, in Thailand, for selling weapons to non-Americans (the FARC guerilla).The FARC guerilla were considered a liberation army not so long ago, similar to the ANC in South Africa, for example, and received foreign aid from many respectable countries. The quarrel there is an internal matter for Columbia to solve - that country is not some kind of paragon of virtue and there is a good reason why the FARC exists, it is their methods that are questionable.
I don't see what Columbia's affairs have to do with the USA either. The only "American citizens" that would be affected would be CIA advisors or elite soldiers who are there meddling in Columbia's affairs. (his supposed crime was "plotting to kill American citizens").
Wait until China arrests an American who meddling in their sphere of interest, brings him to Beijing and sentence him for terrorism, to serve 25 years in a Chinese prison (probably not that much worse than a chain gang in Texas)... Maybe that would make people reflect a bit on the illogical and creepy precedent set by this sentencing. But with people's skewed perspective of reality it would more likely lead to a big political drama and biased media reporting.
And like I said, something like this recently happened to a British man too, and a school boy who hacked a US defense system for fun.
Here is an interesting entry about Victor Bout from Wikipedia
Language genius and Esperanto club member turns terrorist arms dealer... how sad. He'll be a broken man when he gets out of prison in the USA. Assuming he even survives. I guess it's another fallout of the events in the 90s, in the ex USSR. Under different circumstances he would probably have been a really nice and legitimately accomplished person.Viktor Anatolyevich Bout (Russian: Виктор Анатольевич Бут) (born 13 January 1967, near Dushanbe, Tajik SSR, Soviet Union) is a convicted arms smuggler and political prisoner.[1]
Having graduated from the Military Institute of Foreign Languages,[22][27][28] he is said to be fluent in six languages.[29] These include Persian and Esperanto, which he mastered already at the age of 12,[30][31] and in the early 1980's he was member of the Esperanto club in Dushanbe.[32] Bout's personal website states that he served in the Soviet Army as a translator, holding the rank of Lieutenant.[6]
His main crime seems to be that he ignored existing embargos and shipped equipment to whoever could pay. His main fortune was made from shipping and not from weapons sale.