Two weeks ago in Anata, Jerusalem, a Palestinian stood contemplating the rubble of his family home in the winter rain. "Did my house kill anyone that they should do this to me?" he asked. The Jerusalem municipality has 1.5 million shekels left in its demolition budget - enough to level 70 Palestinian homes - and it needs to spend the money before the end of the year. Such demolitions are part of Israel's campaign to create "facts on the ground": the aim is to guarantee Jerusalem's survival as the country's "eternal and undivided capital". Thousands of Palestinian homes in the West Bank, in Gaza and around Jerusalem have been destroyed in the face of international condemnation. Bulldozers have become a weapon of war.
Israel's assault on Palestinian houses is not unique. In times of conflict, civilian homes are invariably singled out for attack. In recent decades, whole villages have been eradicated in various parts of the world, from Saddam Hussein's Iraq to Rwanda and Darfur. But homes are not the only type of building that has been targeted. Countless libraries, museums, churches and monuments have also been destroyed, representing an incalculable loss to the world's cultural patrimony.
Attacks on buildings are often carried out well away from the front line, reflecting their goal. This is not to rout an opposing army. Rather, they are a way of pursuing ethnic cleansing or genocide by other means, a way of rewriting history. Viewed through the eyes of an aggressor, the architecture of the enemy assumes a totemic quality: a mosque is not simply a mosque but a symbol of the presence of a community marked for erasure; a library or art gallery is a cache of historical memory, evidence of a community's historic presence and an emblem of its right to a continued existence.
The havoc wreaked by this type of warfare is not "collateral damage"; it is the active and often systematic destruction of specific types of building or architectural traditions. Invariably, a deliberate twisting of the historical record is involved. After masterminding the murder-ous expulsion of Muslims and the razing of mosques in the Bosnian town of Zvornik in the early 1990s, the mayor told reporters: "There never were any mosques in Zvornik." Throughout the Bosnian war, the country's unique and beautiful Islamic architectural heritage was smashed, burned and bulldozed into pits - sometimes with the bodies of murdered Bosniaks interred alongside.
"The struggle of people against power," wrote Milan Kundera, "is the struggle of memory against forgetting." In my book The Destruction of Memory: architecture at war, I examine this architectural iconoclasm and explore how, in the 20th century, cultural cleansing reflected the fortunes of peoples at the hands of their destroyers. There is no shortage of examples. From Guernica and Dresden to Cambodia and Bosnia, cultural sabotage occurred on an astonishing scale. The Young Turks' genocide of the Armenians was accompanied by the eradication of splendid Armenian architectural monuments, the Chinese conquest of Tibet by the ravaging of monasteries and vernacular buildings.
However, it is Kristallnacht, the Nazis' destruction of hundreds of synagogues on the nights of 9 and 10 November 1938, that stands as the most iconic example of the destruction of memory. Hitler decreed that all physical monuments to the existence of Jews be erased from the townscapes of the Reich.
The Nazis repeated the pattern across eastern Europe, subjecting Slavic culture to a campaign of demolition - Warsaw was razed to the ground, street by street. Kristallnacht can be seen as a proto-genocidal episode, an act of dehumanisation and segregation that paved the way for the horrors of the Holocaust.
The destruction of memory is not only a feature of conventional warfare. Terrorists also target buildings and monuments. In Joseph Conrad's 1907 novel The Secret Agent, Mr Vladimir argues that terrorism (which he calls the "philosophy of bomb throwing") should be directed at the beliefs underpinning a society's understanding of its own prosperity. In Conrad's novel, science is seen as the repository for such beliefs, and so Mr Vladimir arranges for the Royal Observatory at Greenwich to be bombed. In its choice of target for the 11 September 2001 attacks, al-Qaeda was doing something similar: the World Trade Center was the primary symbol of economic power in the primary city of global capital. The cultural historian Khachig Tololyan has echoed Conrad in suggesting: "We need to understand the way in which different societies maintain their vision of their collective selves, and so produce different terrorisms." And, it might be added, different architectural targets. The attacks of 9/11 were, in part, a carefully targeted attack on the "collective self" of the US.
On 2 December, the British government concluded consultations on its intention to ratify the 1954 Hague Convention for the Protection of Cultural Property in the Event of Armed Conflict. The main piece of international legislation aimed at safeguarding the world's heritage during war, the convention forbids the targeting of cultural landmarks except where there is an "imperative military necessity". Despite this loophole, it has taken the UK more than 50 years to sign up to the convention and, to judge from the consultation document, it is now intending to do so largely to protect its own heritage. The US is the only other major power not to have ratified the (admittedly flawed) legislation. No doubt, like the UK, it is wary of the constraints the convention could place on its military operations.
In Iraq, the destruction of archaeological sites of world importance and the burning of Baghdad's Koranic library have demonstrated the price of failing to take these matters seriously. George W Bush's cultural myopia with regard to Iraq's heritage contrasts markedly with the attitude of his predecessor, Dwight D Eisenhower, who instructed field commanders, prior to the reoccupation of Italy during the Second World War, to safeguard that country's historic monuments.
There is, surely, an inescapable link between erasing the physical reminder of a people and actually killing them. The fragility of monuments all over the world should act as a reminder of the fragility of our own capacity to be civilised. "To lose all that is familiar - the destruction of one's environment," wrote Hannah Arendt about the ruins of postwar Germany, "can mean a disturbing exile from the memories they have invoked."
The Destruction of Memory: architecture at war will be published by Reaktion Books (£19.95) on 24 January 2006