Hague’s speech to the International Institute for Strategic Studies was billed last night as the Tory leadership’s most significant overview of its approach to foreign policy as it prepares for government. Hague aims to show that a Conservative government would uphold its commitments to human rights but would ensure that it pursues what aides described as “realpolitik” in foreign affairs. “Foreign policy is above all about the protection and promotion of our national interest, and even narrowly defined the British national interest requires our continued fully active engagement in world affairs,” Hague will say in an echo of Lord Palmerston’s famous declaration. The future prime minister told the Commons in 1848, the year Europe was swept by revolutions: “We have no eternal allies and we have no perpetual enemies. Our interests are eternal and perpetual, and those interests it is our duty to follow.”