The Polk Report goes on to prove that almost all other countries, even the smallest, close the door to Americans. Only Bolivia, Colombia and Costa Rica, which has recently annulled the concessions granted to the _British Controlled Oil-fields_ place Americans and their own nationals on the same footing. The case is different in Guatemala, in Ecuador, and, above all, in Mexico, "only Mexicans by birth or naturalization and Mexican companies have the right to acquire ownership in lands, waters and their appurtenances, or to obtain concessions to develop mines, waters, or mineral fuels in the Republic of Mexico. The nation may grant the same rights to foreigners provided they agree before the Department of Foreign Affairs to be considered Mexicans in respect of such property and accordingly not to invoke the protection of their Governments in respect to the same, under penalty, in case of breach, of forfeiture to the nation of property so acquired. Within a zone of 100 kilometres (62.14 miles) from the frontiers and of 50 kilometres (31.07 miles) from the sea-coast, no foreigner shall under any conditions acquire direct ownership of lands and waters." Meantime the San Remo Agreement had been signed, by which the French Government--voluntarily or no--associated itself with Great Britain in order to drive out America from the Asiatic centres of petroleum production, and delivered over to her the resources which might be discovered in the zones of influence reserved for France. The French Government was so embarrassed about this agreement that for three months it dared not publish it. When it made up its mind to do so, the publication aroused grave anxiety in the United States. The Struggle for Mesopotamia However, public opinion and American official circles followed the progress of the struggle with passionate interest. The situation became even more strained in consequence of an article in _Sperling's Journal_ by Sir Edward Mackay Edgar, which constituted a literal defiance. Great Britain openly boasted of her triumph. "I should say," wrote Sir Edward, "that two-thirds of the oil-fields exploited in Central and South America are in British hands. In the states of Guatemala, Honduras, Nicaragua, Costa Rica, Panama, Colombia, Venezuela, and Ecuador, the great majority of the concessions are in the hands of British subjects and will be developed by our capital.