Aerial bombardment as a doctrine of war was first outlined by the British mathematician and military strategist F.W. Lanchester in his 1915 book, Aircraft in Warfare. Lanchester advocated decisive objectives and approaches to warfare, including bombardment so severe that it would "overwhelm the fire-extinguishing appliances of the community" under attack so that a "city may be destroyed in toto." He also argued, among other things, that the threat of massive retaliation bombing might prove a more effective deterrent to an unprovoked attack than any international law.
Aerial bombardment has obviously advanced since 1915; a nuclear bomb renders the question of firemen quite obsolete, and massive retaliatory power hasn't always prevented unprovoked attacks. The United States' object in aerial warfare is not to destroy cities and civilians but to attack military targets and the installations that support military actions. Lanchester considered his theories about bombing part of a larger theory about traditional warfare, whereas today aerial bombardment (even when it has failed or hit the wrong targets, e.g., the pharmaceutical factory in the Sudan) has been deployed in order to avoid committing Americans troops to traditional wars (as in Kosovo) or to mop up after a course of bombing (as in the Gulf War).
It remains to be seen what role cruise missiles, laser-guided bombs, and old-fashioned iron bombs will play in Afghanistan, since the scale of the attack depends on whether the Taliban are prepared to surrender the leaders of al-Qaida. That surrender, say President George Bush and Prime Minister Tony Blair, is the primary objective of the forthcoming campaign; how the Taliban respond will help decide whether it will be necessary to remove them from power. That said, the effectiveness of aerial bombardment against an army as unconventional as the Taliban's is not certain. They might buckle before a shot has been fired or a bomb has been dropped. Or else they might choose to hide and fight in the three main cities of Afghanistan, where American bombs, deadly and accurate as they may be, would be useless given the unacceptable numbers of resulting civilian casualties. The first major military campaign of the 21st century may therefore be one in which the United States finds itself unable to deploy one of its most effective weapons.