https://iclfi.org/pubs/wv/1183/quote
On 7 November 1938, Herschel Grynszpan, a 17-year-old Polish Jew living in Paris, walked into the German embassy and assassinated a Nazi diplomat. Grynszpan spent 20 months in French prisons before being handed over to the Nazis and transferred to a concentration camp. While rejecting the tactic of individual terror, Trotsky vigorously demanded that Grynszpan be freed from the clutches of the bourgeois state. Similar considerations guide our attitude to the imprisoned Luigi Mangione, who is accused of striking down a capitalist parasite.
We Marxists consider the tactic of individual terror inexpedient in the tasks of the liberating struggle of the proletariat as well as oppressed nationalities. A single isolated hero cannot replace the masses. But we understand only too clearly the inevitability of such convulsive acts of despair and vengeance. All our emotions, all our sympathies are with the self-sacrificing avengers even though they have been unable to discover the correct road. Our sympathy becomes intensified because Grynszpan is not a political militant but an inexperienced youth, almost a boy, whose only counselor was a feeling of indignation. To tear Grynszpan out of the hands of capitalist justice, which is capable of chopping off his head to further serve capitalist diplomacy, is the elementary, immediate task of the international working class!...
In the moral sense, although not for his mode of action, Grynszpan may serve as an example for every young revolutionist. Our open moral solidarity with Grynszpan gives us an added right to say to all the other would-be Grynszpans, to all those capable of self-sacrifice in the struggle against despotism and bestiality: Seek another road! Not the lone avenger but only a great revolutionary mass movement can free the oppressed, a movement that will leave no remnant of the entire structure of class exploitation, national oppression, and racial persecution.
—L.D. Trotsky, “For Grynszpan: Against Fascist Pogrom Gangs and Stalinist Scoundrels” (February 1939)