[Liberty Tree Surgeon]

You realize Joel 3:10 was directed at those AGAINST the Lord? It was a call to have all the heathen bring their might against Jerusalem so the Lord could show his power in overcoming them.

[Vigilanteman]

Yours is a reasonable interpretation, particularly considering that this is the last chapter of the book of Joel, who was a contemporary prophet to Amos, the book which follows.

But both books speak allegorically, so I think there is a double meaning in that this verse may also be directed to the righteous Gentiles, which are us, commanding us to come to the defense of Jerusalem. It was, after all, mostly the righteous Gentiles which saved the Jewish race from extinction.