Recent events in Tunisia and Egypt have focussed attention on the west’s history of supporting allegedly “moderate” or “pro-western” dictators, despite their unpopularity among their own people. Coincidentally, this week has also produced further evidence that the usual justifications given for that practice are bogus.

In Pakistan, a court investigating the 2007 assassination of former prime minister Benazir Bhutto has been told that former military dictator Pervez Musharraf — now living in exile in London — is regarded as a suspect. According to the BBC, the prosecutor charged that:

“two officials told investigators that on the orders of Mr Musharraf they removed a security detail for Ms Bhutto just before she departed the venue where she was speaking in Rawalpindi. She was killed shortly afterwards.”

The rationale that policymakers give for backing a dictators is that the alternative would be worse. If Egypt’s Hosni Mubarak, for example, were to be forced out, his place, we are assured, would be taken by the Muslim Brotherhood, which would establish an Iranian-style theocracy and be hostile to American and Israeli interests.

Leave aside that this view almost certainly mis-states both the strength and the intentions of the Brotherhood. Even assuming it were true, the key point is that American policy has been equally unwelcoming towards more moderate forces. By helping to discredit them or condoning their suppression it has left the field open for extremists.

Pakistan is perhaps the most striking example.

General Musharraf took power in a military coup in 1999. Although Pakistani democracy had a troubled history, the coup was not driven by political instability but by the interests of Musharraf and his fellow generals, and he continued to bend or remake the rules to stay in power for another nine years.

In this he was consistently supported by western governments, and particularly by the Bush administration in the US — especially after Musharraf, with evident reluctance, had signed up to the “war on terror” after the events of 11 September 2001.

This despite the fact that the opposition to Musharraf was primarily secular and democratic: as was confirmed in 2008 when democratic elections were finally held and Musharraf’s opponents won a large majority , just as elections after the death of the previous dictator, Zia-ul-Haq, had brought secular leader Benazir Bhutto to power.

So it would not really be surprising (and indeed it was suggested at the time) if Musharraf had conspired to have Bhutto assassinated. Her existence and popularity was a standing reproach to his rule, pointing out to anyone who cared to notice that he was not the bulwark against extremism that he claimed, but just a bulwark against democracy.

For that very reason, the dictators themselves often show more favor to the anti-western opposition than to the democrats and secularists. It was in Musharraf’s interests to be soft on groups like the Taliban so that he could present himself to the Americans as the only alternative to extremist rule – just as the Brotherhood in Egypt has enjoyed a sort of grudging toleration from the regime.

But the enthusiastic support given to Musharraf, Mubarak and their like throws the “anti-extremist” reasoning into question. It looks as if, for American policymakers, it is democracy itself, in all its messy unpredictability, that is the real enemy.