The two issues that so deeply divided the United States and Europe during President George W. Bush's transatlantic visit last week have this much in common: for both global warming and missile defence, governments need to interpret complex scientific arguments before deciding on a particular course of action.

It is doubly unfortunate, therefore, that Bush went to Europe without a scientific adviser by his side — or even at the end of the phone. Some five months into his administration, the position of the president's special assistant on science and technology, who also runs the White House Office of Science and Technology Policy (OSTP), remains unfilled.

Bill Clinton took just four days to name Jack Gibbons as candidate for the position after his January 1993 inauguration. Bush cannot be judged by that standard: after all, the planning of his administration was delayed by the lengthy dispute over his election last November. But with scientific issues now having more bearing than ever on practical politics, the current delay is eating away at the credibility of Bush's positions on missile defence, climate change, energy policy and stem-cell research. It is also eroding the prospect that the OSTP will ever become fully staffed and functional under the Bush administration: other branches of the White House are greedy for its staff slots, and may soon borrow some of them.

Meanwhile, Bush's critics in the US scientific community — who are not entirely without influence on public opinion — are left to fulminate from the outside over the president's various policy positions. The sooner Bush appoints a respected Republican scientist to head the OSTP, the better are his chances of avoiding embarrassment in forthcoming debates on these positions.