radius of action

The maximum distance a ship, aircraft, or vehicle can travel away from its base along a given course with normal combat load and return without refueling, allowing for all safety and operating factors.

https://www.thefreedictionary.com/radius+of+action, or

Dictionary of Military and Associated Terms, US Department of Defense, 2005, p442


On the other hand, the phrase is also used to mean region of influence of a people or an army in terms of how far they can operate from home and still have a reliable supply line:

It's more of Inner Mongolia even if there was no such geographic concept (IM and OM) at that time, but Genghis Khan and his troops were mostly living and haunting in today Hetao district (in Inner Mongolia), northern Shanxi province and northern Hebei Province. However, you know, during the age of cold arms, a horse is like a tank, the Mongolian warriors had a very long radius of action, so it's not a problem if they planned to cross over the Gobi desert into the outer mongolian steppe/wasteland.


I am not sure that the latter usage is common in English. It's certainly present in historiography in the Hungarian language. (Apparently, military historian Géza Perjés claimed to have invented it.) My gut feeling is that this must have been first a technical term from military tactics for range and it acquired the strategic meaning only later because that is a more abstract concept.

What is the etymology of the phrase: when was it first used, with which meaning and in what context? Which language invented it first? (Cf. the German Aktionsradius in Duden.)

Oxford Dictionaries put its origin to the late 19th century but that's all I have found:


Late 19th century; earliest use found in The Times.


  • Consult a dictionary for "radius" and "action".
    – Hot Licks
    May 11, 2018 at 13:06
  • 1
    @HotLicks That's hardly fair. Given the phrase has an entry in a dictionary, it must be somewhat trackable in it development. May 11, 2018 at 13:07
  • @HotLicks - OP is asking about its earliest usage as an expression and the context in which it was first used. Literal meaning of the two terms is fairly obvious.
    – user 66974
    May 11, 2018 at 13:08
  • Both actio and radius come from Latin but who put the two together for the first time? It could have been done by the Romans themselves but I somehow doubt it because it feels like a modern concept. May 11, 2018 at 13:26
  • 1
    @user3850720 - And the resulting expression is directly derived from those literal meanings. Might as well ask for the origin of "wool sweater".
    – Hot Licks
    May 11, 2018 at 13:26

2 Answers 2


The expression appears to be common especially in military contexts. Its earliest usages, (late 19th century) can be found in the shipping/naval sector in the U.S.A.

From Society of Naval Architects and Marine Engineers (U.S.) - 1894

  • On another passage, having been six months out of dock, she steamed 14.2 days at the same speed, consuming 53.4 tons of coal per day, and reducing the radius of action to 2,995 miles- The York- town, with a clean bottom, one month out of ...

The following 1898 usage is from a print of the Office and Naval intelligence of the USA.

  • In firing at an immovable target the radius of action is determined by the table given in the preceding paragraph, that is. for 23 knots, 330 fathoms (660 yards); for 11 knots, 600 fathoms (1,200 yards), but if the target be movable the radius of ...

I dug into Google Books Ngram Viewer and Google Books a little deeper.

In English, this is the relative frequency of radius of action through time: radius of action, 1800-2008

The local maxima are in 1917 and in 1942.

In the 19th century, there seem to be records in the 1840s‒1850s but I couldn't find a concrete example in Google Books before 1888. radius of action, 1800-1895 Journal of the Royal United Services Institute for Defence Studies, Volume 32, 1888 (here is another link to the article on the publisher's website):

[p880] Now, I should like to ask Mr. Oram if, in estimating the radius of action, this coal consumption is deducted from the total bunker capacity of the ship...

[p883] I think what Mr. Donaldson said about radius of action, and the amount of coal consumed for the engines, is very important. In my opinion as a naval Officer the coal-carrying capacity of these cruizers is not sufficient.

For comparison, here is the same plot for the German equivalent Aktionsradius: Aktionsradius, 1800-2008 The local maxima are in 1912, in 1936, in 1943, in 1958, etc.

Once again, there is a record in the graph at the turn of the 1840s and 1850s. Aktionsradius, 1800-1895

What Google Books dates as a philological publication from 1835 is in fact an article by Hans Herter in the journal Rheinisches Museum für Philologie, Neue Folge [Series 3], 85. Bd. [Vol. 85], 3. H., pp. 193‒239, from 1936. He discusses the abduction of the young Helen by Theseus and considers the radius of action of Theseus. He was based in Aphidnae near Athens, from where he was unlikely to have been able to reach Sparta and the Peloponnesus. According to the original saga, Helen was indeed living in the nearby Rhamnus and not in Sparta.

The paper claimed by Google Books to have been published in the Journal of the German Geological Society, Vol. 103-104, 1849, is another false positive. It talks about the radius of action of magma in reference to the metamorphosis of sediment on the ocean floor. But volumes 103 and 104 were published in 1951 and 1952. It might be a quote from this article.

In the last two examples the year provided by Google Books is the first year when the respective journal was issued, not the publication year of the quoted text.

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