The world has demilitarized by a full order of magnitude since 1945, from 4% under arms to 0.35%

One of the things which intrigues me is the degree of demilitarization across the globe over the past eighty years.  We are definitely not demilitarized (see India and a few other non-OECD countries where today's military is substantially larger than in 1945) but when you compare the standing armies of the major economies today against those in 1939 or 1945, the magnitude differences are astonishing.  

The difference in size and lethality also shows up in the number of troops deployed in various battles and number killed and wounded.  

For example, the Russians and Ukrainians have been slugging it out in Ukraine since the Russian invasion in early 2022 - four years of war.  Roughly the duration of the German-Soviet conflict in Ukraine in World War II.  Bitter and no less existential fighting.  

For a host of reasons though, despite (because?) of the much more lethal weaponry today, the death toll is nearly an order of magnitude less.  The totals are highly disputed and debated but it seems that the combined deaths of both combatants in the current war-to-date is on the order of 350,000-450,000.  

The three month Battle of Kiev in 1941 in WWII alone entailed some 700,000 dead (mostly Soviet.)  A three month battle in WWII in Ukraine resulted in twice as many fatalities as the entire four year war in 2022-2025.  The four year duration of war in Ukraine in WWII saw something on the order of 2-3 million dead for the combined Soviets and Germans.  Compared to 350,000-450,000 in today's war.

We see an even more dramatic ratio with tank losses.  Soviet and German tank losses in the four years of war in Ukraine in WWII were on the order of 50-75,000 tanks.  In the current war the combined losses are on the order of 5,000 tanks.  

Why were the militaries so much larger and the losses so much greater when the lethality of current weapons is so much greater today?  A dozen Abrams tanks today conceivably could have cleared an entire battlefield back then.

All this was brought to mind by this tweet.  

I never knew how badass 1970's German F-104 Starfighters looked. West Germany bought 916 in 1961. 1 in 4 crashed. Grounded by late 1966, upgraded, then limped on until 1991. 292 crashes. 116 dead pilots. Nicknamed "The Widowmaker".🤘😎 pic.twitter.com/8iiuvrvNh9

— Tim Farmer (@timfarmer) December 27, 2025

Which sparked the question as to how many airframes does the Luftwaffe currently field?  916 planes ordered in 1961 (presumably a fraction of total strength) seems a much larger number than my impression today.   The Luftwaffe has had a chronic issue of low numbers of combat ready planes.  Two or three years ago, it was alleged to be only in the mid-double digits.

What about today and using some reasonably encompassing definitions.  How many functional airplanes in the German air force?  Grok:

The German Air Force (Luftwaffe) operates approximately 380-432 total aircraft as of late 2025, including fixed-wing planes and helicopters across combat, transport, training, and support roles.

Let's limit it to combat fixed-wing craft.

This gives roughly 210-230 combat-capable fixed-wing aircraft.

And of these, how many are combat ready?  Grok:

Conservative estimates, based on pre-Zeitenwende trends and partial improvements, suggest 60-80% mission-capable rates for the fleet overall—translating to roughly 125-185 fully combat-ready aircraft at any given time. 

Materially higher than in in 2022 but still, in the scheme of things, minuscule compared to even 1961 much less to WWII when the comparable number was 2,500-3,000 fixed wing combat planes.  The modern nation maintains an air force of roughly 200 combat planes in 2025 versus 3,000 in 1939.  

The broader trend of global demilitarization is generally desirable.  Obviously there are lots of tactical and geographic exceptions but smaller militaries are generally desirable.  

How many people were under arms in 1945?  Grok:

At the peak of WWII in 1945, the total mobilized military personnel (active and under arms) worldwide was vastly higher, with estimates of ~90-100 million personnel in uniform across belligerent nations. This reflected total war mobilization, including conscripts and support roles.

Over the entire war (1937-1945), approximately 127 million people were mobilized globally (cumulative total who served).

And today?  When the global population has ballooned from 2.3 billion in 1945 to 8.2 bullion in 2025?  

The total number of active-duty military personnel worldwide in 2025 is approximately 27-30 million. 

[snip]

2025 active personnel (~28 million) is roughly 25-30% of the 1945 peak (~90-100 million).

The world population has increased by 244% but the global military presence has shrunk by 75%.  A phenomenal reduction in armed presence.  Granted - our far more lethal crop of weapons might be much more an expense on the nations than those in WWII but that is not a slam dunk assumption given the massive expense of battleships, aircraft carriers, tanks and the like.  

All this is to say that the globe has a dramatically smaller military footprint than in 1945.  

In crude, best estimate numbers, in 1945, about 4% of the world was under arms.

In 2025, about 0.35% of the world is under arms.  

An order of magnitude less militarized than we were.  

A thousand other ways of looking at this.  Of particular interest is the greater distribution of militaries outside of those countries which are considered modern or developed (some of whom are now reasonably modern such as India) compared to 1945.  For example, among the top fifteen countries with the largest militaries who were not independent or modern in 1945, there are:  India, North Korea, Pakistan, Iran, Ethiopia, South Korea, Vietnam, Egypt, Indonesia, Brazil, and Thailand.  All sorts of risks associated with those countries, every one of them with a military larger than 360,000 men.  Only four of the largest militaries today (China, Russia, USA, and Ukraine) were also among the largest militaries in 1939.  Europe has effectively demilitarized.  

France, at 23rd in the world has a military the same size as that of Morocco at about 200,000.