One other relevant issue seems to have emerged during this time-- the American gun lobby and NRA starts to advertise the 2nd Amendment as a constitutional guarantee for international weapons sales in our domestic market. German/Swiss/Austrian gun manufacturers (Sig Sauer, Glock, H&K) and American (Colt, Remington, Smith & Wesson) suddenly started to flood the market with military and police-grade small arms.
What's interesting here is the economics. The US can spend MORE money in a given year on weapons (in absolute terms), and a given weapons company can have more revenue in a given year from the sale of weapons (in absolute terms), but the actual profitability of the company declines, due to the gradual inflation in the price of key resources, labor, living expenses and the like.
It is true that the US is spending, each year, almost as much as we did each year during our involvement in WW2, in terms of absolute amounts of money. From 1943-1945, we spend about $900 Billion (in 2005 US dollars) per year on the military. Today, spend about $600 billion per year. That said, the United States has far more people and is far, far richer than it was in WW2. Furthermore, we've had massive inflation since then. That's why a comic book cost a penny in 1941, but costs $6 today. (It was 75 cents when I was a kid in the late1980s----there has been a much more rapid inflationary pressure on comics, as with other goods, since the 1980s).
What's the purpose of all this? First, the US military budget is clearly enormous in terms of absolute numbers. But relative to our GDP, its actually the smallest its been since the 1930s during the height of the Depression.
Second, that the same holds true for all the other Great Powers from WW2---Germany, Britain, France, Russia, China, Japan.
Third, that many old armament industries, facing a dramatic but gradual de-escalation in military spending since the end of the Cold War (look at % of GDP, not absolute dollars, so we can control for the influence of monetary, as well as cost-push inflation), have looked to alternative markets to maintain their economic competitiveness. Their revenue is up in absolute terms, but so are their costs. As such they faced ever shrinking margins after 1968.
Fourth, that our current gun-control issue in the United States is actually related to these overall international, geopolitical trends. The giant armament industries we propped up during WW2 and the Cold War basically see domestic arms sales (as well as international arm sales to developing nations) as a key way to remain economically viable.
In a sense, the NRA has been transformed into a lobbying group for military contractors seeking to pass military surplus, and civilian modified weaponry onto civilian markets, because the US doesn't rely as much on large bodies of infantry in order to pursue the national interest. (increasing spending is increasingly geared toward robotics, computers, drones, etc....) And those infantry that remain, are far more deadly, man for man, than their counterparts 100 years ago. Due to tech advancements, a single US Marine today has the firepower of an entire WW1 infantry regiment. That means you need fewer men per mile, and it costs less (in relative terms), because you get more bang for your buck per soldier. Defense contractors hate these market efficiencies, because much profit is still based on volume.
Many pacifists on the left can't see this problem, because they wish to radically reduce US military spending, and reinvest it on domestic programs. That's a legitimate and noble political position, but in advancing said position, they focus almost entirely on the US Defense Budget in absolute terms, failing to take into consideration that we currently spend far, far less on the military, relative to GDP, than we have in 70 years, irrespective of Reagan's boost in defense spending.
The reason we have so many mass shootings in the US, and why there is such increasing instability in many regions of the developing world, is due to the fact that the Cold War ended and all the Great Powers have reduced military spending to between roughly 3% and 5% of GDP, even as those GDPs have consistently risen. This means less profit for arms companies. And hence they are dumping their product in the US and throughout the world, in order to continue being profitable.
All these issues are interconnected. The reason we don't see it is due to our poor state of mathematical education.
Because the U.S. GDP has grown over time, the military budget can rise in absolute terms while shrinking as a percentage of the GDP. And an arms company can have triple the revenue it had in 1945, and have far more profits, but still be less profitable, due to their margins. The margins are key.