Joel and The Day of the Lord

The book of Joel is about two days, two events. The first is The Day of the Locust: a locust infestation of unprecedented severity, but this was only the prelude to something far, far worse: The Day of the Lord. The challenge in understanding Joel is to distinguish between these two occasions. In Joel’s day the former had already happened, but the latter loomed on the horizon and could have been averted. Was it?