I think there is little doubt that there have been opportunities to use this weapon many times under Presidents Bush and Obama. It was never used. That is almost certainly because there was a fair amount of resistance to doing so. President Trump was not going to say no. No way. It’s impossible not to see this as something that would just appeal to Trump. “I dropped the biggest conventional bomb in the history of war.” Of course Trump okayed it.
Here’s one other thing that I have not seen mentioned.
We are currently in a tense brinksmanship with North Korea. If we did get into a military confrontation with North Korea, a big part of that would almost certainly be destroying heavily, heavily fortified facilities tied to the nuclear weapons and ballistic missile programs. I’m not a military expert. I don’t know the precise mix of primary blast versus concussion wave, the technical issues with destroying a nuclear weapons facility with the potential to spread nuclear contaminants, how deep the blast goes in fortified underground facilities, whether it’s good at destroying deep, reinforced bunkers rather than tunnels created by low tech paramilitaries, etc. etc. But I have a very hard time believing the decision to use this weapon was not in some way influenced by the desire to send a signal or play a bit of psychological warfare with the North Koreans. The technical issues don’t necessarily matter. If you want to rattle the North Koreans it can work anyway. They don’t know all the technical realities, limitations or how risky a game we might be willing to play. It may be enough to send the signal that Trump doesn’t operate by the rules of his predecessors. Maybe I’m wrong. But it’s a helluva coincidence.
Late Update: A number of readers have noted that this bomb tends to be for surface destruction or near surface. The Air Force has a different bomb for deep hardened bunkers. So it probably would not be the bomb you would use in North Korea. Still, I think the psy-ops argument is pretty much the same: We’re using stuff we’ve never used before. We have a President who doesn’t say no.