BARACK OBAMA, we are told, chose Joe Biden to be his running mate because he needed an older man, more experienced in foreign policy, to fill the gaps in his resume and reassure American voters that the United States would be safe under an Obama presidency.

That's true, but it is assumed that he also chose him because Biden's views on foreign policy are not radically different from his own. Since American foreign policy still affects almost everybody in the world that makes Biden's views very interesting.

Joe Biden, now 65, has been a senator since he was 29. For almost half that time he has been a member of the Senate Foreign Relations Committee, which he now heads. He has been around long enough to leave plenty of evidence about his view and his reflexes, and it is safe to say that he qualifies as a liberal interventionist (or, as they say on the other side of the Atlantic, a liberal imperialist). He has never met an international problem that he didn't think the US should help to solve.

Unlike the neo-conservatives, who are brothers under the skin to the liberal interventionists, Biden does not believe that every problem in the world can be solved by the application of US military power, but he does think that many of them can. He backed the US military intervention in Bosnia, the bombing of Serbia during the Kosovo crisis, the invasion of Afghanistan after 9/11, and the invasion of Iraq (although he subsequently had the grace to admit he was wrong and apologise for that).

On larger issues, by contrast, Biden has usually been a voice of moderation among the chorus of Democratic hawks vying to outdo their Republican colleagues in their hostility to Russia and their enthusiasm for the war on terror. He did support the expansion of NATO right up to Russia's frontiers (and visited Georgia immediately after the recent fighting), but he has resisted the temptation to paint Russia as the Soviet Union in sheep's clothing.

Terror is a tactic, Biden has said. Terror is not a philosophy. It is a mantra that everybody in US politics should be required to chant each morning before work, even if it is slightly inaccurate. (Terror is actually an emotion. Terrorism, however, is a tactic, a political tool or technique, more precisely — that can be used in support of a wide variety of causes. It is as misleading to declare war on terrorism as it would be to declare war on propaganda.)

Knowing this has enabled Biden to concentrate (most of the time, at least) on the need to eliminate the particular groups of terrorists that had attacked the United States, who were mostly located in Afghanistan and Pakistan. When he briefly supported the invasion of Iraq, he did not do so out of an ignorant belief that Saddam Hussein had links with those terrorists.

 It was his liberal interventionism that drove his decision, combined with a naive belief that the US intelligence services would not bend the evidence on Iraq's alleged weapons of mass destruction to serve the president's purposes.

So that is Joe Biden's take on foreign policy, and it probably isn't vastly different from Barack Obama's. The difference lies mostly in the experience factor, which tells you all you needed to know about the value of experience in these matters. It is Biden's long residence at the heart of the Washington political/military/intelligence machine that makes him such a conventional character.

All that stuff about Obama being not ready to lead is simply a coded warning that he might not lead in the time-honoured, conventional way. John McCain certainly would, and so would have Hillary Clinton if she had won the Democratic nomination The selection of Joe Biden as his running mate is intended to allay those fears by linking Obama to someone who is deeply embedded in the conventional wisdom, but it doesn't actually prove that Obama is too.

There is still room for suspicion that Barack Obama harbours a secret desire to take American foreign policy in a quite different direction, away from the traditional great-power realpolitik and the occasional forays into liberal interventionism. That would probably appal Biden, and it would horrify the rest of the Washington establishment.

Vice-presidents don't have a veto, so the choice of Biden poses no problem there. But the Washington establishment probably does have a veto, so whatever Obama intends, Biden will not be disappointed by the outcome.