Well, nobody wants it to happen again, but unfortunately it does, again and again. Not long ago I switched on the TV at random and saw maps of the Balkans with big arrows of invasion surging up through them.
I thought it was something to do with Nato bombing, but then I saw it must be mid-afternoon history time on the BBC, because a picture of a Roman soldier appeared and a voice said: "The Roman Empire had always had trouble in Dacia and now they set out to pacify the Dacians again... "
The big boys have been trying to pacify the Balkans for at least two millennia. The only time there has been peace seems to be when some major imperial power came along and behaved very badly. Hello, Roman Empire. Hello, Turkish Empire. Hello, Austro-Hungarian Empire. Hello, very briefly Nazi Germany. Hello, Soviet Union. And now, Hello, Nato.
Except that Nato's action doesn't quite fit the pattern. Nato is not intending to march into the Balkans and knock heads together.
All Nato intends is a bit of long distance bombing, which does look good on TV. But we are also getting a lot of politicians on the box who are being asked what the game plan after the bombing is, and who are unable to think of anything.
The conversation usually goes a bit like this: "So, Mr Cook, what happens after the bombing?"
"We are knocking vital chunks off the Yugoslav war machine so that the Serbs cannot continue with their atrocities."
"Yes, but they are continuing with their atrocities."
"We are delivering a message to Mr Milosevic to make him understand he cannot go on as he is."
"But he is going on as he is."
"And he knows that we will go on with the bombing until eventually he gets the message."
"And what happens after the bombing?"
"We are knocking vital chunks off the Yugoslav war machine so that the Serbs cannot continue with their atrocities." And then the tape loop starts again.
This is not the sort of interview you would have got at the beginning of the Turkish invasion of Europe all those years ago: "So, Sultan, you intend to go into Central Europe and shoot and bomb all those Albanians and Greeks into submission, till they stop fighting?"
"Do you have a game plan for after that?"
"Yes. We are going to run the place with an iron hand and stay there for hundreds of years, shooting them whenever they start fighting again, making them convert to Islam and generally behaving like real bastards."
"Will you ever leave?"
"Never. Unless Lord Byron comes along and liberates them."
So what Nato is doing is a little different from what previous invaders have done. But is there any kind of precedent for all these Nato hit and run raids?
Curiously enough I think there is, and I think it is in my own house. Upstairs from where I work there is a spare room to which my 11-year-old son retires from time to time, often with friends, to play computer games.
From what I can make out, they play two kinds of games. One, not very common, is the kind in which the players have to build a civilisation and get points for its construction. In the much more common kind, the players get unlimited ammunition and have to destroy everything that moves.
When they are in full session, the distant sound of bombing, shooting and dying comes non-stop, just as on a clear day I can also hear through my window the distant firing from Salisbury Plain 20 miles away. Then the smoke of battle clears, and my son and friends come out, innocent and cherubic, cleansed by the mayhem, ready to take the dog for a run.
I sometimes think that the way Clinton and gang operate their weaponry overseas is more like a PlayStation programme than real history. Bang! Bomb Baghdad. Bang! Bomb Libya. Bang! Bomb a factory in the Sudan.
The dust clears. Game Over. Do you wish to keep the details of this game? No, we'll start again from scratch next time with another enemy, without learning anything.
"Mr Clinton, what are you going to do after the bombing?"
"We're going to take a rest. Then we'll switch on the machines again and bomb somewhere else. Then we'll take the dog for a run."
Let's hope it works. But sometimes I worry.