And yet few historically literate people understand the intimate workings of the alliance system prior to WW1[1] - but it is a vital piece of background information that explains a lot about what happened.
In my view, "the great powers had alliances and went to war to support one another" sums it up reasonably well, despite ignoring viral things like the 1839 Treaty of London[2], etc.
For someone studying post-Vietnam US history (say), I think the Kahn summary might be a reasonable background. Probably not sufficient in itself, but reasonable.
It is an overview, but absurdly condensed. A skill like calculus can be thought in brief, clear overviews; you either understand _it_ or you don't.
History is no such _it_.