Memorandum by the Legal Adviser (Hackworth) to Mr. Charles A. Timm of the Division of the American Republics

Dr. Timm: The Inter-American Arbitration Treaty of 192964 provides for the arbitration of differences of an international character [Page 619] which have arisen or may arise between the parties to the treaty by virtue of a “claim of right made by one against the other under treaty or otherwise” which it has not been possible to adjust by diplomacy and which are juridical in their nature by reason of being susceptible of decision by the application of the principles of law.

I agree with Mr. Lawson that there is at present no question to arbitrate.

I say this for the reason that we have offered to negotiate a treaty allocating to Mexico a fair share of water, even more than Mexico was using or would have been able to use with the river in a state of nature, and there is not now any reason to suppose that the matter cannot be adjusted by diplomacy if Mexico takes a reasonable attitude. Should these negotiations prove abortive because Mexico claims more water than we are willing to make available, she might then say that there exist differences of an international character by virtue of a claim of right which it has not been possible to adjust by diplomacy; that those differences are juridical in their nature since they are susceptible of decision by the application of principles of law, and demand arbitration. While the principles of law in this particular field are somewhat vague and nebulous, we probably would not feel disposed to decline arbitration. I should not in that event greatly fear arbitration, although we can never be certain how an arbitral tribunal may react to a given state of facts, for the following reasons:

It is my understanding that Mexico is now receiving more usable water than she received prior to the construction of Boulder Dam;
It is also my understanding that had the river been left in a state of nature she probably could not have utilized a greater amount of water because of the nature of her terrain, the uncontrolled flood conditions, etc.;
She is not entitled to claim the benefits of our ingenuity and expense in the harnessing of the waters of the river, but rather would as a matter of law be entitled only to such additional benefits, if any, as would have been available to her had we not constructed the Dam;
If we should arbitrate we would probably argue (a) that we have a right to use all waters having their source in the United States, and (b) that in any event Mexico cannot claim the benefits of our action in controlling in our own interest flood waters which were damaging both to Mexico and the United States.

I should suppose that Mexico realizes the weakness of her position and is merely referring to the possibility of arbitration with a view to driving a better bargain.

Green H. Hackworth