It was not, however, so plain how American interference could be justified.

The problem was obviously a difficult one and did not concern the United States alone.

Latin America was even more vitally concerned with it, and her statesmen, always lucid exponents of international law, were active in devising remedies.

Carlos Calvo of Argentina advanced the doctrine that "the collection of pecuniary claims made by the citizens of one country against the government of another country should never be made by force." Senior Drago, Minister of Foreign Affairs in the same country in 1902, urged upon the United States a modification of the same view by asserting that "the public debt cannot occasion armed intervention." President Roosevelt handled the matter in his messages of 1903 and 1904.
"That our rights and interests are deeply concerned in the maintenance of the [Monroe] Doctrine is so clear as hardly to need argument.

This is especially true in view of the construction of the Panama Canal.