No, We wont support concessions that will be revoked when the threat calms down, and whenever socialists and moderates worked hand in hand, the social democrats ended up betraying them and leading to the victory of reactionnary forces afterwards.
In France in 1830, radical revolutonnaries overthrew Charles X, only to be betrayed by the liberals to instal Louis-Philippes and essentially just change the flag.
And when he got overthrown in febuary 1848,
there was a short time of peace, but the life conditions didn't improve much for the workers so they striked, and in June, the provisional govenment of Cavaignac and Lamartine murdered them, leading to the rise of the Parti of Order and Louis-Napoleon Bonaparte.
in 1870, profiting of the French defeat in the Franco-Prussian war, Parisian workers rose up, the new republic of social democrats and conservatives murdered them.
During the Russian revolution, social democrats and Bolsheviks rose together against the Tsar, but the new governement was a liberal one, that wished to continue to send young men to their deaths against the Germans.
in the german revolution, the social democrats used proto-fascists freikorps against communists revolutionnaries, leading to the rise of the nazis…
And this continues to this day, in Spain, the social democrats funded fascists terrorists to kill basque civilians, in the Uk they did it with loyalists terrorists. It's the same thing all the time, fact is, social democracy is just the moderate wing of fascism, it serves the same purpose, to stop a revolution…