In a comment, Wiggins at Opposed Systems Design asked how the CRS report on US interventions abroad from 1798-2007 would make one reconsider the Core/Gap concept. Stealing this from my answer in his comments, I'd say that I didn’t mean "reconsider" in the sense of “thinking about discarding”, more like “think about again in broader/historical context”.
The Map was made as an extrapolation of data for US military deployed man-days 1990-2003; in the CRS report we have data for a rough cut for a historicized version. One would, of course, to make this systemically useful have to add up the (other) great powers’ deployments and interventions … and you would wind up describing hard-end trends in the colonial spread of the modern, industrial state. And thus, looking at the different interventions, you would get some perhaps interesting trends in the relative size and frequency of industrial vs. colonial (or big vs. small) wars), in the vein of - or supplementing - Rupert Smith’s great The Utility of Force.
That kind of reconsidering. The (problems related to) spread (and models) of the modern state is really at the heart of almost all security related politics. So historical trends and discussions hereof are interesting.