JF Ptak Science Books Quick Post
Out of the many references I've seen for war gaming in early-ish computer journals and reports from the RAND corp (and other such places before, say, 1962) I don't think I've ever since a direct visual connection between three-dimensional gaming objects and a computer. But here are two examples,in the same journal and within a few dozen pages of each other, one featuring chess pieces and the other featuring toy soldiers. Both are obvious selections, but not used very often at all in illustration.
Games of war and capture go far back, with chess many hundreds of years old and Go older still. Early war games as "war games" appeared in the late 18th and early 19th century, developing past Strategoes (in the 1880's) with other iterations, and then famously in two mass culture works by H.G. Wells, Little Wars (1911) and Floor Games (1913).
[The two Wells works may be found here and are well worth looking at: http://www.gutenberg.org/ebooks/3691 (Little Wars, though fair warning here of the unfortunate but time-laced subtitle, "(A Game for Boys from twelve years of age to one hundred and fifty and for that more intelligent sort of girl who likes boys' games and books") and then http://www.gutenberg.org/ebooks/3690 (Floor Games)]
And a second image, from a few months later: