In that same interview, Colby insists that the war with Iran is not a stalemate, partly because time is on our side, and partly because Trump has lots of options to escalate if necessary. As to the latter point, I would simply ask: (a) what are those options? and (b) if they exist, why haven’t we already used them?
In reality, you know the options–nukes, conventional terror bombing, and a ground invasion. Colby makes it clear that the last of these is not on the table. That leaves the other two, even if he doesn’t admit it.