Even confined to a narrow slice of military history, the hammer and anvil tactic is a fascinating one, thought to originally be developed by Philip II of Macedon, in a bid to make creative use of the Greek phalanx to pin and grind down the enemy, which would serve as the backing anvil to allow delivery of the smashing hammer blow with a mobile and swift cavalry, brought up against the enemy's weakened and preoccupied flank.
The metaphor works for a great many more things, especially concerning the manipulation of hard things, which is best done up against the support of even harder things. The literal hammer and anvil in forging is obvious enough, but one useful example I have in mind is the process of splitting firewood. If you swing an axe down upon a log that is just sitting in the dirt, you may get it to split, depending on how hard the ground is, but a lot of that energy is traveling down into the soil itself and compacting it, and so you are losing a fair amount of energy from that axe blow in the process. Place that log upon a harder surface though, say a stump, and more of that energy is going to be concentrated in the log itself, and want to go laterally as opposed to straight down, making the axe blow more effective.
With this image of the old metaphor in mind, I wanted to turn to the underlying relations in historical transformation and change. As we explored previously, any given crisis or great process of transformation necessarily takes place upon a landscape that has a certain shape, carved and shaped through previous processes of transformation and crises, and the shape of that landscape influences the direction of change that that process will take, given the pressures and forces it is subjected to.
What is hard and solidifying and what is mushy and fragmenting influences where the energy is going and what things will do when subjected to that energy. A great crisis may make a rising empire or break a declining one, for example.
I'm also getting to a meta point about the project here, which I've repeated ad nauseam here: none of this is easy. The analysis of anything depends on everything else related to it, and then the act of analyzing necessarily constricts one's field of view, possibly obscuring pertinent issues elsewhere. One does what one can, and then an occasional deep breath here and there and letting go for a minute could be just as useful.