The definition of symbiosis has varied among scientists. Some advocated that the term symbiosis should only refer to persistent mutualisms, while others thought it should apply to any type of persistent biological interaction (in other words mutualistic, commensalistic, or parasitic).
The League of Nations failed for a couple of reasons: 1  The United States was not part of it. 2  More importantly, the countries in the League did not take the idea of collective security seriously.3  When countries attacked others, nothing was done. 4  For example, Italy attacked Ethiopia and Japan attacked China. The United States was not part of it. 2  More importantly, the countries in the League did not take the idea of collective security seriously. 3  When countries attacked others, nothing was done. 4  For example, Italy attacked Ethiopia and Japan attacked China. 5  In both cases, nothing serious was done.
The League of Nations has been a disappointing failure.... It has been a failure, not because the United States did not join it; but because the great powers have been unwilling to apply sanctions except where it suited their individual national interests to do so, and because Democracy, on which the original concepts of the League rested for support, has collapsed over half the world.