Look at the preceding years. Wow. Try again Mr V.
Furthermore, here's the site:
Military Spending: How Much is Enough?
Let's see what they write under the graph:
After Vietnam, during the Nixon and Ford administrations, military spending decreased by nearly a third from its peak during the war. A modest increase during the Carter administration was then followed by a huge increase in military spending during the Reagan and Bush I administrations that was not justified by any external threat. Along with huge tax cuts based on crank supply-side economic theory, the big military buildup produced by far the biggest budget deficits since WW II. As the chart below shows, Reagan/Bush basically borrowed 100% (and more) of the money that was being spent on troops and armaments. (Deficits shown are "unified" budget amounts plus the amount borrowed from trust funds, taken from published government sources, as adjusted by the Senate Budget Committee). Note that negative deficit values, as plotted, are actually surpluses.