If we look generally at this question of the status quo from the international point of view during the past two centuries, we find two divergent and irreconcilable lines of treatment.
The jurists and the writers have generally considered that the status quo is or ought to be sacred from the point of view of outside attack.[[16]] In most of the books the question is treated under the heading of "Intervention" and, perhaps with some qualifications, the writers do not admit the legality of intervention. They make exceptions on the ground of self preservation of the intervening State, sometimes on the ground of protection of human life and so on. But, at least with these exceptions, they generally maintain that the State against which the intervention is directed may legally object to it—that is, may legally insist upon the maintenance of the status quo (or of its right, in a proper case, to change the status quo[[17]]) and furthermore that such a State might justly, if able (as it usually is not), resort to war against the intervention.
On the other hand, the history of international affairs during this period is quite to the contrary.[[18]] Over and over again States, sometimes individually, sometimes some of them collectively, have interfered with the affairs of another State with which they Had strictly no legal concern, on many different occasions and on all sorts of pretexts. They have defended such intervention at times on the vague grounds of the rights of humanity, the interests of commerce, the restoration of order and so on.
Any one who is familiar, even in a cursory way, with the history of Europe will be able to recall numerous such instances; and it must in fairness be admitted that in some of them the result has seemed beneficent.[[19]]
And it must not be forgotten that it is not only the wicked powers of Europe that have acted along these lines. In reference to the affairs of other countries, though not its own, the United States has maintained this privilege of paternal intervention by force. We maintained it, for example, in Cuba in 1898, chiefly on the ground of the sake of humanity.[[20]] In connection with the Panama Canal, Mr. Root set up the famous proposition[[21]] that the sovereignty of Columbia over the Isthmus was limited and qualified by the general right of mankind to have a canal between the Atlantic and the Pacific, and to have that canal kept open for the commerce of all.
Many other instances might be cited. It is, however, worth while to recall in connection with this alleged limited right of sovereignty of Columbia over part of its territory that the United States subsequently paid $25,000,000 to the owner of the qualified fee.
It is perhaps unnecessary to add that this alleged right of intervention, as between great powers, was recognized by another name as a method of changing the status quo, namely, the method of war.
The effect of the Protocol is unquestionably to consecrate the international status quo with a definite position of legality, not to be disturbed by force.[[22]] The views of the writers, as opposed to the practice of Great Powers, have been adopted.
Article 2 of the Protocol forbids a resort to war[[23]] as against any other State, a party to the Protocol, "except in case of resistance to acts of aggression."[[24]]
Under Article 8, every Signatory agrees to abstain from any act which might constitute a threat of aggression.