Last Night's Viewing: Secret Pakistan, BBC2; The Impressions Show, BBC1

Kipling called it right in Kim. "When everyone is dead the Great Game is finished," he wrote, "Not before." That was 110 years ago and since then the players have changed several times.

For a while, the Americans took over from us against the Russians, but then the Russians got bored and withdrew. And now, if Secret Pakistan is to be believed, it's the Americans versus the ISI, Pakistan's secret intelligence agency. The question of whether Secret Pakistan is to be believed, incidentally, is raised not because of any doubt about the professionalism of those who made the programme, but because penetrating the fog of false representation that obscures the view in this region of the world is a very tricky business.

Take one of Secret Pakistan's star witnesses, for example, a Taliban commander who insisted that the ISI had given material help to forces fighting against the coalition inside Afghanistan. Since he was described as "still fighting Western forces", it was initially something of a puzzle as to why he would be revealing this information to a Western journalist. What was his motive? Did he feel that undermining confidence in Pakistan's intelligence services would be damaging to his enemy? Or was it possible that the ISI was now a greater threat to him than American troops? The fog swirled but never entirely cleared.

A few things were obvious. Nobody seems to trust the Pakistanis. As the killing of Osama bin Laden demonstrated, the sovereignty of this staunch ally isn't taken with any great seriousness in Washington. American drones attack targets in Pakistan and American guns fire across the border when they deem it necessary to protect themselves. At the same time, the coalition forces in Afghanistan need Pakistani co-operation.

After an earlier falling out over drone attacks, the Pakistani government temporarily suspended the supply transports over the border and American troops found themselves on short rations. It's also clear that terrorist attacks in India and Afghanistan have been launched with the help of Pakistan-based groups, and possibly the ISI itself. But again, what was slightly opaque was motive. Why was it that Obama's surge in Afghanistan was met by an equivalent surge in secret Pakistani support for the Taliban? And what advantage did they see in keeping Osama out of the US's reach?

There was a hint of an answer about the latter question. With Bin Laden gone, the biggest obstacle to peace negotiations with the Taliban in Afghanistan has also vanished. And some elements in the Pakistani intelligence services seem to fear that possibility. In a pointed contrast to Bin Laden's long untroubled residence in the country, Mullah Baradar, a Taliban leader who was showing signs of being willing to come to some kind of deal with the Americans, was arrested almost immediately.

With the Americans in Afghanistan, it occurs to you, the Taliban is fully occupied outside Pakistan's borders. But if the Americans went, it isn't difficult to see where the insurgents might apply their lethal energies next, and how easy would it be for a Pakistani government to call on American aid then? This intriguing and depressing documentary was mostly concerned with whether the Americans can trust Pakistan. It might have been even more illuminating if it had spent a bit of time on the question of whether Pakistan can trust the US.

What happened to impressionists? There was a time when it was the blue-chip form of light entertainment, and no weekend or Christmas was complete without a special. But the steam seems to have gone out of it a little these days. The Impressions Show has its moments (Debra Stephenson gets that mad vamp off Dragons' Den to a T and Jon Culshaw nails Paul McCartney and Prince Charles). But all too often if you close your eyes you wouldn't have a clue who was being lampooned. It gives an impression of being entertaining, but not always a convincing one.