One measure: Take the question of publicly held debt as a percentage of GDP.
Certainly, the closer that debt gets to 100% of GDP, the larger this risk looms.
Fundamentally, we should be asking for governments to spend 0.2 percent of GDP on research and development into green energy.
One way of answering the question is to look at trendline growth in GDP compared to the anticipated size of any looming recession.
Yes, Washington should be aiming to leave the federal government's share of GDP near the historical norm of 18-20 percent.
Germany's economy collapsed following a reparations agreement, which sapped and consumed less than 10% of its GDP.
But this is one of the lowest rates in the world (c. 40% of GDP).
Up to 15% of their GDP is in the form of handouts, soft loans and technical assistance.
Some of them cost the country more than 10% of its GDP each (for example, the crisis of the bank shares in 1983).
Allocating three percent or less of GDP for defense could easily prove to be a ceiling and not a floor.