Sentence:  Had the situation been reversed , had , for instance , England been the enemy in 1898 because of issues of concern chiefly to New England , there is little doubt that large numbers of Southerners would have happily put on their old Confederate uniforms to fight as allies of <WSD>Britain</WSD> . 
Meaning of the word marked with <WSD> tags:  a monarchy in northwestern Europe occupying most of the British Isles; divided into England and Scotland and Wales and Northern Ireland; `Great Britain' is often used loosely to refer to the United Kingdom