Porto Rico and our determination to build an Isthmian canal made a large American navy inevitable. Great Britain realized, therefore, that she would have to cast about for future allies. It was on considerations of this kind that she signed the Hay-Pauncefote treaty with the United States in 1901, and the defensive alliance with Japan in 1902. In view of the fact that the United States was bent on carrying out the long deferred canal scheme, Great Britain realized that a further insistence on her rights under the Clayton-Bulwer treaty would lead to friction and possible conflict. She wisely decided, therefore, to recede from the position which she had held for half a century and to give us a free hand in the acquisition and control of the canal at whatever point we might choose to build it. In signing the Hay-Pauncefote treaty she gracefully recognized the fact that the United States had paramount interests in the Caribbean which it was unwise for her to contest. Since the signature of that treaty American supremacy in this area has not been seriously questioned. The determination to build a canal not only rendered inevitable the adoption of a policy of naval supremacy in the Caribbean sea, but led to the formulation of new political policies to be applied in the zone of the Caribbean--what Admiral Chester calls the larger Panama Canal Zone--that is, the West Indies, Mexico and Central America, Colombia and Venezuela. The policies referred to included the establishment of protectorates, the supervision of finances, the control of all naval routes, the acquisition of naval stations, and the policing and administration of disorderly countries. The advance of the United States in the Caribbean since the Spanish War has been rapid. The acquisition of Porto Rico and the establishment of a protectorate over Cuba were the natural outcome of that struggle. In 1903 we acquired the canal zone under circumstances already described. The following year President Roosevelt established financial supervision over the Dominican Republic. In 1915 the United States landed marines in Haiti and a treaty was soon drafted under which we assumed financial supervision and administrative control over the affairs of that country. In 1916 we acquired by treaty from Nicaragua an exclusive right of way for a canal through her territory and the lease of a naval station on Fonseca bay, and in 1917 we acquired by treaty from Denmark her holdings in the West Indies known as the Virgin Islands. These successive steps will be considered in detail.