Understanding the brain. That's what you have to do in a guerrilla war. Find out how it works, what it's trying to do.
Ramadan? An attack on US headquarters in Baghdad and six suicide bombings, all at the start of Ramadan? Thirty-four dead and 200 wounded? Where have I heard those statistics before?
And how could they be so well co-ordinated - not sophisticated, perhaps, but well-timed, down to the last second? And why the Red Cross?
I knew that building, admired the way in which the International Red Cross staff refused to associate themselves with the American occupation - even at the cost of their lives, because the guards outside their Baghdad headquarters carried no guns.
So here's the answer to question one. Algeria. After the Algerian Government in 1991 banned democratic elections that would have brought the Islamic Salvation Front to power, a growing Muslim revolt turned into a blood-curdling battle between the Islamic Armed Group - many of its adherents cut their battle teeth in Afghanistan - and a brutal Government army and police force. Within three years, the Islamists - aided, it seems, by army intelligence officers - were perpetrating massacres against the villagers of what was called the "Blida triangle", a three-cornered territory around the Islamist city of Blida outside Algiers.
And the worst atrocities - the beheading of children, the raping and throat-cutting of women, the slaughter of policemen - were committed at the start of Ramadan.
At Ramadan - newspapers like to call it the "holy fasting month", which is accurate up to a point - Muslim emotions are heightened.
In these most blessed of days, a Muslim feels that he or she must do something important so that God will listen to him or her.
There is nothing in the Koran about violence in Ramadan or, for that matter, suicide bombers - any more than there is anything in the New Testament urging Christians to carry out the genocide or ethnic cleansing at which they have become experts in the past 200 years - but Sunni Wahabi believers have often combined holy war with the "message", the "dawa", during Ramadan.
So what was the message? In Baghdad, the political message of the weekend was simple.
It told Iraqis that the Americans cannot control Iraq; more importantly, it told Americans that they cannot control Iraq.
Even more important, it told Iraqis they shouldn't work for the Americans. Who wants to be an Iraqi policeman this morning?
It also acknowledged America's new rules of combat: kill the enemy leaders.
The United States killed Saddam's two sons (and grandson).
It has boasted of killing al Qaeda members in Afghanistan and Yemen, just as Israel kills Palestinians in Hamas and Islamic Jihad.
So was it by chance that the Black Hawk helicopter shot down in Iraq was hit over Tikrit just after Paul Wolfowitz had passed through town?
And the assault on the al-Rashid Hotel - a far more efficient version of the rocket attack more than six weeks ago - almost killed Wolfowitz. He was "a room away" from one of the missile explosions.
The architect of the Anglo-American invasion of Iraq was almost assassinated by America's enemies. Did they know where he was sleeping in the hotel? Given the number of Iraqi staff in the al-Rashid, probably.
And then there is the Red Cross, the last neutral humanitarian organisation - after the double suicide attack on the UN - which might have provided some communication between the US and its antagonists.
Now it, too, has been smashed.
Some of America's enemies may come from other Arab countries, but most of the military opposition to America's presence comes from Iraqi Sunnis - not from Saddam "remnants", "diehards" or "deadenders" (the Paul Bremer cover-up titles for a real and growing Iraqi resistance), but from men who in many cases hated Saddam.
They don't work "for" al Qaeda. They don't work for Mullah Omar or Osama bin Laden.
But they have learned their own unique version of history. Attack your enemies in the holy month of Ramadan. Learn from the war in Algeria. And the war in Afghanistan.
Learn the lessons of America's "war on terror". Go for the jugular. "Bring'em on." Kill the leadership. You're with us or against us, collaborator or patriot. That was the message of yesterday's bloodbath in Baghdad.
ęCopyright 2003, New Zealand Herald