The quarter century after the Treaty of Utrecht in 1713 was peaceful, with no major wars, and only a few secondary military episodes of minor importance. The main powers had exhausted themselves in warfare, with many deaths, disabled veterans, ruined navies, high pension costs, heavy loans and high taxes. Utrecht strengthened the sense of useful international law and inaugurated an era of relative stability in the European state system, based on balance-of-power politics that no one country would become dominant. Robert Walpole, the key British policy maker, prioritized peace in Europe because it was good for his trading nation and its growing British Empire. British historian G. M. Trevelyan argues: