Have any successful insurgencies later been defeated by a previously defeated foe?

Has there ever been a historical precedent in which a successful insurgency group that eventually comes to power is later defeated by their former foes by conventional means (national army vs. national army)? What I mean is, has it ever happened that a guerilla group drives out the superior force, comes to power, takes control of the nation’s army, government, infastructure, etc. (thus losing their guerilla status), then gets attacked and defeated by traditional means by the country (or group backed by another country) that they previously ousted?

There’s the Khmer Rouge in Cambodia. They were toppled by the Vietnamese army, which had previously backed them. Does that count?

How about the English civil war? Cromwell ousted the monarchy and established a republic of sorts, which a few years later was overthrown and a new king installed.

I’m pretty sure that Nicaragua will work for you. The whole history of the country, from the time of it’s liberation from Mexico in the 1830s, to the establishment of a real modern republic in the 1990s has been a history of rebel groups coming into power, using guerilla warfare or back door dealings to overthrow the goverment, only to have the same happen to them. The anti-Sandinista Contras in the 80’s are perhaps the most famous example of American intervention, but we stuck our noses in the country pretty much for 150 years, often supporting either current governments, or the opponents, and changing our minds relatively frequently.

Wikipedia gives a confused, but relatively complete explanation of the power trades, but let me recommend Arturo Cruz’s “Nicaragua’s Conservative Government” as a book that really goes into all the various revolutions, anti-revolutions, restorations and rebellions.

How about the Taliban in Afghanistan? (The OP didn’t say that the deposed national army couldn’t get assistance from the world’s largest superpower.) Although I’m not sure I’d call the Taliban an insurgency…

I guess that would be the same for a lot of Latin American countries, especially Colombia.

I don’t know if I’d call the Tajik warlords the former rulers of Afghanistan, either.

Rabbani was the president of Afghanistan prior to the 1996 Taliban revolution/insurgency/whateveryouwanttocallit, and he had some kind of leadership position – political spokesman? figurehead? – at the top of the Northern Alliance.

French history has plenty of examples:

The Bourbons were deposed in the French revolution (which, though not guerillas, were a populuar rebellion), but came back into power in 1814, were deposed by Napoleon briefly (who had been deposed himself), and came back again. They were deposed by the Orleanists (a branch of the family), and the Orleanists were then deposed by the Bonapartists. One of the issues of the Dreyfuss case were that you had three groups (Bourbons, Orleanists, and Bonapartists) who all laid claim to rule the country, and two of them had been deposed before and had come back.

In English history, there was Henry VI, who was deposed by Edward IV. Henry (or rather, his wife), eventually gathered an army and deposed Edward, who regrouped and threw out and killed Henry.