An advanced civilization, like ours could be in a couple of hundred years, realized that the most challenging time in their history was when they had the knowledge to make global changes, but not the wisdom to see the consequences of their actions. (In our history this is the time from the beginning of the 20th century to the end of the 21th century. WW1 and WW2, cold war, terrorism, global warming, population explosion leading to famines and pandemics, etc.) They want to help others to overcome these difficult times.

But how can they do it?

Sending high power radio signals to every habitable planet, for millions of years continuously, is not an option, because it is just another form of pollution. Listening to, and answering, radio signals is difficult, because the answer may reach those emerging civilizations too late, if they are not within a 50 light-year radius of one of the automatic answering stations.