In 2004, then-Defense Secretary Donald Rumsfeld called al-Jazeera’s news coverage “vicious, inaccurate and inexcusable.” Nowadays, with a memoir on the market and views to share, he finds the news channel’s airwaves more appealing.

He agreed to appear on al-Jazeera English on a show hosted by the British journalist Sir David Frost that will be aired Friday.

“Its audience has grown and it can be an important means of communication in the world and I am delighted you are doing what you are doing,” he tells Frost, according to excerpts released by the channel.

The interview covers religious extremism, foreign policy and other issues, at times sounding less bellicose than he did during his time in office. Rumsfeld says the danger posed by radical Islam is equal to the way that “extremism in Christianity or extremism in Judaism is a danger.”

He also questions the effectiveness of the U.S. war against al-Qaeda and other groups, saying that “we are not competing in that competition of ideas very successfully.”

The relationship between al-Jazeera, which is supported by Qatar’s royal family, and American leaders has been complicated by suspicion and mistrust. In April 2003, the channel’s Baghdad bureau was hit by U.S. aerial bombing, killing journalist Tareq Ayyoub. American forces said they were responding to firing coming from the building. A similar incident in Kabul in 2001 destroyed a building that housed al-Jazeera offices, though no fatalities resulted. Then-director Wadah Khanfar said last year that the bombings were an American attempt to stifle the channel’s independence.

Most American cable companies do not offer access to al-Jazeera’s English-language service, an omission Khanfar attributed to “misinformed views about our content and journalism” in an article earlier this year. But U.S. diplomatic cables made public by WikiLeaks show that Khanfar often discussed al-Jazeera’s coverage with U.S. officials. His resignation last week prompted news reports suggesting that the revelations led to his departure, a charge the channel denied and that Khanfar said he found entertaining.

As waves of revolutions rocked the Arab world earlier this year, the networks’ coverage has become increasingly popular. Many Americans watched the coverage online, and a campaign has begun to demand broader access to the channel in the United States.