The German base at Kiao-chau held out for more than two months in 1914, without any external aid.

During all the time of siege, even if surrender is ultimately to occur, the enemy's forces are prevented from being utilized elsewhere.
This condition was clearly shown during the siege of Port Arthur, because the large force of Japanese troops required to conduct the siege were urgently needed in Manchuria--to which region they were sent as soon as Port Arthur fell.
From this point of view, naval bases again look much like fortresses on the land; fortresses like Metz and Strasburg, that had to be subdued before an enemy could safely pass them.
_Strategic Position of Distant Bases_ .-- Since the strategic position of an outlying naval base is the principal factor that goes to make its value, it may be well to consider what elements make a strategic position good.
To make the problem clear, let us take a concrete case, that of our own country, and consider what elements would constitute a good strategic position for a naval base of the United States, leaving out of consideration for the moment any questions of resources and military strength.
In the case of a war with a nation that had only one naval home base, it is clear that the best position for our distant base would be one as close to the enemy's base as possible; because, if placed there, our fleet, if it were the more powerful, could do more to injure the enemy's fleet, or prevent its going out, than if placed at any point more distant from the enemy's base; and if it were less powerful, it could do more to cut the enemy's communications, because it could attack them at or near their source.
A poor position would be one far away from both countries, and far away from the line joining them.

In the case of a war between this country and Norway, for instance, a very poor position for a naval base would be a spot near--say Juan Fernandez--in the south Pacific.
In case the enemy country has two home bases of equal importance, the best position for our base clearly would be one equidistant from them, and as near to each as practicable.

If the distance from our base to a point half-way between the two bases is shorter than is the distance to it from either base, then a fleet at our base could probably prevent the junction of two forces issuing from those two bases--assuming, of course, that we had a proper system of scouting.

Our fleet would be able to operate on what are often called "interior lines"-- a technical expression that has great efficacy in confusing a simple matter.