I suppose that an alternative interpretation of the sixth trumpet would be to see it as announcing the French Revolution, and, more generally, the advent of secularisation.  On this account, the loosing of the angels at the Euphrates, that is, the elimination of the protective shield between the Church and the World, would be identified with the dissolution of Christendom.  The precise ‘day and hour’ when everything kicked off might be identified with the decision of King Louis XVI not to break up the self-appointed tennis-court assembly, or perhaps with his own execution. 

On the other hand, while the Revolutionary wars, and the wars of national self-aggrandizement which they spawned, killed a large number of people, it does not amount to ‘a third of mankind’, at any rate, not yet.  There is also the point that secularisation is a logical consequence of Protestantism, and in that sense M. Robespierre and his friends would seem to pertain rather to the fifth trumpet than to the sixth.  Gregory XVI implies this in Mirari vos:

This shameful font of indifferentism gives rise to that absurd and erroneous proposition which claims that liberty of conscience must be maintained for everyone. It spreads ruin in sacred and civil affairs, though some repeat over and over again with the greatest impudence that some advantage accrues to religion from it. “But the death of the soul is worse than freedom of error,” as Augustine was wont to say. When all restraints are removed by which men are kept on the narrow path of truth, their nature, which is already inclined to evil, propels them to ruin. Then truly “the bottomless pit” is open from which John saw smoke ascending which obscured the sun, and out of which locusts flew forth to devastate the earth. 

The great march of mental destruction will go on. Everything will be denied. . . . Fires will be kindled to testify that two and two make four. Swords will be drawn to prove that leaves are green in summer. . . . We shall fight for visible prodigies as if they were invisible. . . . We shall be of those who have seen and yet have believed (Chesterton in 1905).

Today is perhaps the worst day for Christian civilisation since the fall of France to the freemasons in the 18th century. If I were an American citizen I should certainly be hoping for a secession of the healthier states from the tyranny now being exercised from Washington D.C. Let the whole land-mass be shared between two entities, a real State and the pseudo-state. One cannot live with such people. They are brain-washed. They are more like zombies than human beings. This is not like the co-existence of Catholics and pagans in the Roman empire. The pagans did not by their laws abolish marriage and the family, or even dream of such a thing.

One can pray for these people and do penance for them; one cannot live with them in society.

Having spent several hundred pages excoriating the French Revolution, Edmund Burke becomes at last ironically emollient:-

I do not deny that among an infinite number of acts of violence and folly, some good may have been done. They who destroy every thing certainly will remove some grievance. They who make everything new, have a chance that they may establish something beneficial.

When I read this, I couldn’t help thinking of Vatican II. Of course, there can never be a true revolution in the Church, since her constitution is divinely guaranteed. Still, they changed almost everything they could: the Vulgate, the rite of Mass, the rites of all the sacraments, the rites of all the sacramentals, the rite of exorcism, all the hours of the divine office, the code of canon law, the constitutions of all the religious orders, the rosary, the calendar. Among all these quasi-revolutionary acts, was anything good achieved? The only thing that comes immediately to my mind is the restoration of the authentic hymns in the breviary, undoing the classicizing revision of the 17th Century. However, the authentic hymns had always been maintained in the breviaries of religious orders, anyhow.