What were the strengths and weaknesses in the military formation of the Great Powers during World War I?

The two opposing military alliances of World War I were the Entente Powers and the Central Powers. The Entente Powers were composed of France, Great Britain, the United States (after 1917), Italy (after 1915), Russia (until 1917) and Japan. The Central Powers were made up of Austria-Hungary, Germany, the Ottoman Empire, and Bulgaria. We will discuss their relative strengths and weaknesses below.
Entente Powers
Strengths
Taken together, these nations had large overseas empires to call on for material and personnel. Great Britain and France, in particular, had many colonies all over the world, particularly in Africa and southeast Asia. Laborers from these colonies, as well as some combat troops, greatly augmented the fighting forces of the Entente. Also, to support their previous imperial conquests, France and Great Britain had large and technologically advanced navies that would serve their alliance well during the war.
Russia did not have the large empire of its allies, but it did have a large domestic territory and a huge population. It was able to use its resources and large army to its advantage.
The United States and Japan were able to strengthen the alliance in a way that the other members could not. Since the war was not being fought on their soil, the manufacture of war materials and supplies was not disrupted.
Weaknesses
The Entente Powers were geographically spread out from each other. This meant that to supply their allies, each member nation had to risk a dangerous and lengthy ocean crossing. It also made communication more difficult.
Russia started off the war as a strong ally in terms of manpower and supplies, and Russia had the advantage of having a strategic eastern front. However, it soon proved to be as much of a liability as an asset. Internal unrest and a weak political structure led to a revolution that overthrew the tsar in 1917. The Central Powers were able to take advantage of this situation and by the end of the year, Russia was out of the war.
The Central Powers
Strengths
The Central Powers all shared borders with each other. Being contiguous, they were more easily able to supply each other with aid and personnel. This also made communication fast and simple.
Germany and Austria-Hungary had a strong military tradition long before the start of the war. They had large, well-equipped and well-trained armies that they were able to call upon as soon as hostilities began.
Weaknesses
Before the surrender of Russia, the Central Powers were fighting a two-front war. Having to divide resources between a western and eastern front was a major disadvantage.
While Germany did have a modern navy, taken as a whole, the naval powers of the Central Powers were no match in terms of size to those of the Entente.
In addition to fighting external enemies, Austria-Hungary was also beset by internal ethnic conflicts. It had to contend with several rebellions during the war that diverted a lot of its resources.
Even though they had banded together to form military alliances, there had been long-standing political tensions between all the members of the Central Powers. These historic tensions made the powers distrustful of each other and weakened their alliance's overall effectiveness.
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