estaban decreciendo
-they/you were decreasing
Imperfecto progresivo para el sujeto ellos/ellas/ustedes del verbo decrecer.

decrecer

Solo unos pocos años distan el volverse claro que la revolución estaba decayendo, que las convulsiones sociales estaban decreciendo, que el orden capitalista estaba siendo restaurado gradualmente.
Only a few years after it became clear that the revolution was decaying, that social convulsions were decreasing, that the capitalist order was gradually being restored.
Palabra del día
crédulo