More generally, the phrase can describe the problem confronted by any Great Power trying to wage a major war in a distant place.
Here is a quotation from an official US Gov't report, The War with Germany: A Statistical Summary, published in 1919. It's available online:
The stream of supplies going forward to an army may be likened to the water delivered against a fire by an old-fashioned bucket brigade. For every pailful thrown on the fire there must be many that have been taken from the source of supply and are on the way. As the distance from the source increases this supply in transit constantly grows. When an army is 3,000 or 4,000 miles from its sources of supply the amounts of supplies in reserve and in transit are enormous as compared with the quantities actually consumed each month.
I was just talking about "wastage" in the Russia thread. For the USA to maintain any given wastage rate at the battlefront, the USA would need to have a multiple of that wastage rate "in the pipeline." To fill that pipeline, the USA would have to greatly outproduce its distant opponent. This is all the more so, given that offensive operations, to be successful, usually demand a significant margin of strength over the enemy, and entail a higher wastage rate.
In other words, one must not draw the facile conclusion that the mere entry into the war of a major industrial power such as the USA would be decisive in itself. One cannot merely assume that victory is inevitable, from a glance at the apparent gross advantages in terms of aggregate indices of population, resources and production.
A large proportion of the USA's gross resource and industrial advantage was negated by the inherent geographical inefficiency of its strategic location.
If gross resource indices were what mattered most, then after three years of war the Entente should have already defeated the Central Powers, because the British, French and Russian Empires together possessed from the outset a big aggregate advantage in men, material, and productive plant.
Instead, what was happening was that the Central Powers, operating on strategic interior lines, were able to confront, in detail, serial increments of enemy strength that were each insufficient to clear the threshold of superiority needed to defeat them.
The story of time and space, in relation to how human and material resources are applied to war, is a story that tells us just how critical it was to have an industrialized country in the alliance, which did not suffer from geographical inefficiency.
In the Great War, the country in the alliance whose output could go more or less directly to the battle zone was France. In the Second World War, the country in the alliance whose output could go more or less directly to the battle zone was the Soviet Union.
The Danger of Historiographical Retrojection
In WWII, the USA became the "Arsenal of Democracy." After WWII, the USA was a "superpower." After the Cold War, the USA became far and away the mightiest hegemonic power in all of human history.
It is therefore understandable that an observer in the early 21st century would be prone to regard the effort of the USA in the Great War, in the light of what happened subsequently. There is a tendency to retroject the image of a world-striding power back upon the USA of a century ago.
One can certainly study the USA's effort in the Great War as an origin of many later developnents. Indeed to understand those later developments, one must do so. However, there is an important difference between studying the USA's effort in the Great War as a starting point for later things, and retrojecting an image of later things upon the USA's effort in the Great War. The study of origins is done with advantage to one's understanding of what comes after, but the retrojection of latter developments can addle one's understanding of the past.
As usual I've gone on at length, as the plodding bricklayer of the walls of text. In later posts on this thread I'll add illustrations of how the USA in the Great War, although already of course a Great Power in an absolute sense, was nevertheless a very inadequate war machine relative to the demands of that time. The USA of WWI was not the USA of WWII.