The United States is massively building up its potential for nuclear and non-nuclear strikes in Latin America and the Caribbean by acquiring unprecedented freedom of action in seven new military, naval and air bases in Colombia. The new US push is part of an effort to counter the loss of influence it has suffered recently at the hands of a new generation of Latin American leaders no longer willing to accept Washington's political and economic tutelage. President Rafael Correa, for instance, has refused to prolong the US armed presence in Ecuador, and US forces have to quit their base at the port of Manta by the end of next month. So Washington turned to Colombia. The country has received military aid worth $4.6bn (2.8bn) from the US since 2000, despite its poor human rights record. Colombian forces regularly kill the country's indigenous people and other civilians, and last year raided the territory of its southern neighbour, Ecuador, causing at least 17 deaths. This being US foreign policy, a tell-tale trail of oil is evident. The fact that the US gets half its oil from Latin America was one of the reasons the US Fourth Fleet was re-established in the region's waters in 2008. The fleet's vessels can include Polaris nuclear-armed submarines - a deployment seen by some experts as a violation of the 1967 Tlatelolco Treaty, which bans nuclear weapons from the continent. With or without nuclear weapons, the bilateral agreement on the seven Colombian bases, signed on 30 October in Bogota, risks a costly new arms race in a region.