Of course the imperial character doesn't just emerge ready-made out of a vacuum. The frustrated and humiliated late-imperialist does have a few things right about the general character of the people that existed in the vaunted golden era of a given imperial power, and these characteristics tend to be similar across time, such as the hardiness and vigorous aggression required of the struggling founding generations to clamber their way to the top of the heap.
The reality of such a multitude of circumstances involved in the rise of an entire empire is much more complex of course: great imperial powers tend to arise out of periods of great upheaval and constant warfare, wherein the coalescing warring powers are eventually reconciled and then centralized, out of interest of generating a longer term stability.
But the act of gazing wistfully back into history, or looking into the future for that matter, always involves some compression, and necessarily happens in the time and place that the thinker is doing the gazing, assisted by the available tools of analysis and concerns and cultural and historic perceptions at the time, and so a whole lot is left out in the final analysis.
As for the compression, the humiliated late-imperialist pulls from the complex flow of history a few simplified symbols, cobbling them together so as to suggest a glorious restoration to past heights. But this is a superstition comparable to their own projected contempt of the cargo cults attempting to emulate their power.
The moment has already passed. And indeed, it was a large and unwieldy moment: no one is going to get that bull by the horns. It was a unique set of historical circumstances that led to the rise of the imperial power in question.
And the nature of imperial power follows the basic mimetic tendencies of our strange reality. When one acts in the world, the world begins to respond in kind to oneself. The towering imperial power evokes in the Other (as a multitude, not a monolith) not only feelings of defensiveness and antagonism, but all kinds of other feelings like envy as well, which can be based on anything from the desire of power to a pragmatic need for self-protection.
The moment that the powers of violence flowing outwards begin to weaken, the other aspiring imperial powers make their moves and consolidate their own power, overtaking the old oppressor. The flow of imperial power is by its nature unidirectional and irreversible in this way; it is the nature of the beast.
The crisscrossing threads of history's forces tend to snap individual actors in and reinforce their trajectories. To tear out of the lattice completely is to unravel the whole thing, though this does eventually happen of its own accord, after which it begins to reconstitute itself again.
