What's the deal with r/AskSocialists have extreme fluctuations from 1.6 million subscribers to 40k something subscribers?

Saw this post on the sub regarding the r/Conservative and I just realized the same thing happened to r/AskSocialists but even more if a severe drop in subscribers.

The post: https://www.reddit.com/r/OutOfTheLoop/comments/1tbzgda/whats_going_on_with_rconservative_theyve_lost/

Last year r/AskSocialists only had 30-50k something weekly but during the peak of the Iran war these past few months i noticed a colossal spike in activity going from 30-50k to 1.6 million and dropped to the former around the beginning of april.