England has no eternal friendships, only eternal interests

I hold with respect to alliances, that England is a Power sufficiently strong, sufficiently powerful, to steer her own course, and not to tie herself as an unnecessary appendage to the policy of any other Government. I hold that the real policy of England—apart from questions which involve her own particular interests, political or commercial—is to be the champion of justice and right; pursuing that course with moderation and prudence, not becoming the Quixote of the world, but giving the weight of her moral sanction and support wherever she thinks that justice is, and wherever she thinks that wrong has been done…I say that it is a narrow policy to suppose that this country or that is to be marked out as the eternal ally or the perpetual enemy of England. 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… And if I might be allowed to express in one sentence the principle which I think ought to guide an English Minister, I would adopt the expression of Canning, and say that with every British Minister the interests of England ought to be the shibboleth of his policy.

Lord Palmerston, Liberal Foreign Secretary, House of Commons (1 March 1848).