The repercussions of the invasion of Iraq continue. They might be compared to the spreading ripples caused by a stone thrown into a pond - except that, in this case, the waves seem to get progressively higher, not smaller. There is not only the increasing chaos in Iraq but also the growing evidence that America's "war on terror" exacerbates the threat of terrorism.

These repercussions were underlined by this week's television - not only in documentary but also in drama. Britz (Channel 4) told a story about two British Muslims from Bradford - brother and sister - who develop different responses to being second-generation immigrants. The brother works for MI5, because he wants to help Britain, which he regards as his country. His sister, alienated by Britain's foreign policy and the prejudice against Muslims, sides with the suicide bombers. The drama was written and directed by Peter Kosminsky, who gave us The Government Inspector - about the death of Dr David Kelly (another subject that won't go away).

Kosminsky's new drama was equally thought-provoking, although its length (four-and-a-half hours spread over two nights) made it an endurance test. The acting was impeccable but the plot development was often unclear and laborious. Yet it was worth watching, as it showed many sides of a complex situation and it was generally well-balanced, illustrating the injustice of Britain's anti-terror legislation as well as the bigotry on both sides. Unfortunately Kosminsky seemed at the end to come down on the side of the suicide bombers, apparently justifying the violence which will inevitably lead to more violence.

The invasion of Iraq was supposed to replace Saddam Hussein with a democratic regime which would be a source of stability in the Middle East. But No Plan, No Peace (BBC1) - a Panorama special - showed how neither the US nor the British governments had a proper strategy to deal with the post-war situation in Iraq. They knew that creating a new Iraq would be "the most complex nation-building project since Germany after World War II" but they had inadequate plans and resources. Lawlessness was accompanied by a lack of services like water and electricity, which alienated the Iraqi people and opened the way for warring factions to start the civil war which further undermines stability in the region.

"If you have an aggressive foreign policy, invading other countries, it's hardly a surprise that you get an aggressive reaction." This truth was reiterated in Clash of Worlds (BBC2) by a historian who was actually talking about the Indian Mutiny of 1857, although his words are very relevant today. This was the first of three programmes looking at past conflicts between Britain and Islam. The first programme described the mutiny which arose in India from Muslim (and Hindu) fears that traditional beliefs were under threat from the Christianity introduced by the British colonialists. The programme drew a modern lesson: that "The perpetrators of acts of violence against the west believe they are righting the wrongs of history, fuelled in many cases by a sense of injustice from the actions of Britain's imperial past."

Some wise words about conflicts between groups were spoken in Doug Stanhope, Go Home, a programme in Channel 4's very patchy "Comedy Lab" series. Doug Stanhope, an American comedian, was filmed in Edinburgh talking about the illusions behind racism and chauvinism. He memorably summed up: "Nationalism is nothing but teaching you how to hate people that you never met."

Politicians too seldom realise that they are sowing the seeds of their own discomfiture. George Bush made life difficult for himself by invading Iraq but he has shown his ineptitude in other ways. American Nightmare (BBC2) described how Bush encouraged banks to offer home loans to low earners. He was hoping to foster home ownership but instead the 'sub-prime' mortgages fuelled a huge number of repossessions. This unsettled the international money markets as well as causing immense misery for those who were evicted from their homes.