Andrew White got his blue Iraqi badge on Wednesday – the pass that allows him to move around Baghdad. The Anglican Chaplain to Iraq supported the US invasion – he still thinks Saddam shipped his weapons of mass destruction off to Syria before the Anglo-American armies arrived – and as someone who used an American pass to get about, the end of the occupation must have contained a special irony. "From the day the Americans left, their passes didn't work any more. I couldn't do anything. But now I've got the new Iraqi badge. It's fine."

White says he has even asked for Iraqi nationality. "They won't let me. Iraqis come to London and five years later they're British. I've been here for 14 years. Why can't I be Iraqi?" I ponder this one. He's of Anglo-Indian stock and looks a lot more Iraqi than many Iraqis. But I doubt if his citizenship – his wife's great-great grandfather was foreign secretary Joseph Chamberlain – is exactly at the top of the al-Maliki agenda in Baghdad.

I like Andrew White. He's larger than life, brave, a combination of a quote-a-day preacher, Martin Luther, Terry Waite and a Vicar for All Seasons. I find myself gasping at his mixture of frankness and wire-tripping, criticising the Iraqi Christian clergy as well as Muslim prelates – "That's the problem with this place, everyone thinks they're in charge" (that was his Maundy Thursday sermon) – and I suspect he might be more popular with his friends in Islam than his brothers in Christianity.

His work for Muslim-Christian reconciliation (in Baghdad, Alexandria, Copenhagen, Coventry, you name it) while ministering to a flock in Baghdad he simply can't protect is somewhat close to that old cliché: awesome. He's lost members of his church council to kidnappers (11 in one day in 2005, between Fallujah and Ramadi, and never seen again), seen his flock murdered in the streets, even his own security guards killed, 270 of his congregation murdered in five years; for months, he lived in the notorious Green Zone, freighted by armoured cars and armoured men to and from St George's Church in Haifa Street.

St George's is Andrew White's cathedral, his parish, his "heaven" – his word, and I'll keep it that way – and was built to commemorate the British and Commonwealth dead of the 1914-18 war. Its fine stained-glass regimental windows were long ago shattered by bombs, and even the remaining plaque to "one million dead who fell in the Great War" has been gashed by shrapnel.

In 2009, a bomb in Haifa Street that killed 164 Iraqis sent arms and legs sailing through the empty windows of St George's. Now its garden boasts a small pyramid to commemorate eight Danish soldiers killed in Iraq between 2005 and 2008, a tiny reminder of the cost in Western blood of the Bush-and-Blair arrogance of power. A Christian population of one and a half million has been reduced to 200,000, courtesy of a born-again Christian from Texas.

But then up pops the ornery side of Andrew White. He patiently explains that his church received financial help from the Americans under Bush. "That all stopped when Obama took over." The collapse of the Christian minority is a tragedy which the West has still not faced. It is now scattered across Sweden, Jordan, Lebanon, Syria, America ... Andrew White now runs a reconciliation council which includes Yazidis, Turkmen, Mandiens (followers of John the Baptist), Messihis, Faili (Shia) Kurds, you name it. He regards senior members of the Sunni and Shia clergy as his friends. The fatwa against all sectarian killings was partly his work.

But then suddenly, White becomes the country parson, tut-tutting at our lack of faith. General Angus Maude ("liberator" of Great War Baghdad) and Gertrude Bell, one of the inventors of Churchill's Iraq, are both interred in the British cemetery. "Maude only came to our church once and then he died of cholera (he didn't boil his milk) and he is buried in our cemetery. Gertrude Bell is buried in our cemetery – but never came to our church!" Suddenly, White's the imaginary Vicar of Aynsford (where he was born), questioning our need for Christian burial if we lack Christian faith. I smile weakly. White also cares for Iraq's seven remaining Jews, angrily telling me that a US cable released by WikiLeaks identified all by name, complete with their home addresses. "They are quite frightened," he says. As the French say: J'imagine.

It's impossible not to admire White. He's a media man to his bones, of course, but he's also a scholar, a former medical doctor who studied Hebrew at Cambridge, Rabbinics at Mea Sharim, speaks Hebrew and used to speak Yiddish. In Iraq, most Christians speak Aramaic. White points out that there is a Jewish shrine for Ezekial (Dhu Alkafel for Muslims) between Babylon and Najaf, now a Shia shrine. "The imam from there comes to this room and chats to me."