Secretary general echoes US concerns about Europe and says UN ‘must be ready’ to step in when Gaddafi falls Nato’s secretary general has warned that continued disparity in US and European defence spending might lead to a “two-tiered alliance” in which American and European troops would not be able to fight effectively together. In a Guardian interview, Anders Fogh Rasmussen echoed the fears expressed last week by the US defence secretary, Robert Gates, about the strains being put on Nato by unequal burden-sharing. “Ten years ago US defence investment represented almost half of all defence expenditure in the whole alliance. Today it is 75%,” Rasmussen said. “This increasing economic gap may also lead to an increasing technology gap which will almost hamper the inter-operability between our forces. The Americans provide … still more advanced military assets and equipment; the Europeans are lagging behind. And eventually it will be difficult to co-operate even if you had the political will to co-operate because of the technological gap.” He added: “All this may in the long run weaken our alliance.” Rasmussen said such a decline in Nato was not inevitable, expressing the hope that European nations would “step up to the plate” to increase defence spending. He also said the pooling of resources in bilateral and multilateral arrangements could make up for the decline in defence spending in difficult economic times. In the short-term, he said the US had stepped in to provide more ammunition for the campaign in Libya in the face of the rapidly dwindling supplies of its European allies, and insisted that Nato now had everything it needed to maintain the campaign at “high tempo” for the next three months. Beyond that, Rasmussen vowed that the alliance was “prepared to continue as long as it takes to accomplish our mission”, to protect Libyan civilians and ultimately force Muammar Gaddafi out of office. But he admitted concerns about the sustainability of operations carried out by a minority of Nato members. “Of course it is a matter of concern that only eight allies are conducting air-to-ground strikes. If we are to ensure the long-term sustainability of the operation we should also broaden the support for the operation,” Rasmussen, a former Danish prime minister, said. “The American people ask, and legitimately so, why should we carry the heavy burden to ensure international peace and stability. You also profit from it, so you should also take your share in the burden. That’s Secretary Gates’s message. I share that message.” However, Rasmussen argued that after two and a half months of intensifying Nato air strikes and deepening political isolation, the Gaddafi regime was facing collapse. “It may take some time but it could also happen tomorrow and we have to be prepared for that.” Once Gaddafi fell, he said, the United Nations should be ready to take the lead in managing the transition and be prepared to do so without Nato ground troops. “Firstly we do not envisage a leading Nato role in that. On the contrary we want to see the UN co-ordinate and lead the post-Gaddafi effort,” he said. “Actually I can’t imagine Nato troops on the ground and I think it’s also important to send that very clear message to the UN and other organisations right now so that appropriate plans can be in place in due time and the Gaddafi regime can collapse soon.” Nato officials are increasingly concerned that the UN is not ready to take responsibility for the transition, and worry that UN officials assume that Nato, having led the military campaign, will continue to take lead responsibility by default. “The UN normally take three months to plan for this kind of transition and we don’t see much activity so far,” one official said. Rasmussen said Nato could support a UN-led post-Gaddafi transition, logistically and from the air, but he laid down three conditions for such support: there had to be a demonstrable need for a Nato role, there had to be a clear legal mandate and there had to be Arab support for a continued Nato presence. Jan Techau, head of the European office of the Carnegie Endowment for International Peace, said European and other states were making individual plans for assisting any transition, but he warned that the assumption that the Gaddafi regime was on the point of collapse might be premature. “We are increasingly hearing sceptical voices over whether this military operation can be brought to a successful conclusion. That is the biggest nightmare at the moment,” he said, adding that the constraints on the UN mandate for the Nato role and a lack of ammunition were the main problems. Nato Libya Middle East Africa Foreign policy Julian Borger guardian.co.uk