Where did the term "long game" come from?

...Where did this expression come from? Why is it so popular? The second question is relatively easy to answer. It is a vivid metaphor for an idea that frequently comes up in consideration of politics, business, and other human endeavors: to wit, the possession and use of a long-term strategy. (The very phrase “long-term,” so flat and overplayed, suggests the need for a replacement.) It sounds British, always a good thing. And catchphrases, no less than videos or memes, have the capacity to go viral: to attain uncanny popularity at the drop of a dime.

But where did “the long game” come from? My investigation (admittedly not exhaustive) suggests that it is indeed of British origin. Certainly there are plentiful uses in such sources as The Economist, The Times (of London), and The Times Literary Supplement. The most common contexts have been diplomacy, espionage, and statecraft, as in a 1944 comment in The Times that “ … so well and successfully have conspirators played the long game.”...