Chivalry does not govern international relations even at the present day, and in 1845 sentiment was perhaps less tender on the subject than it now is. Vattel, the recognized authority on the law of nations, wrote thus: “Every nation ... has, therefore, a right ... to preserve herself from all injuries.... When the evil is done, the same right to security authorizes the offended party to endeavour to obtain a complete reparation, and to employ force for that purpose, if necessary.”[33]
Moreover, the United States could appeal, not only to strict law, but still more forcibly to broad equity. To sum up the case in one sentence, Mexico, our next neighbor, on no grounds that could be recognized by the United States, repudiated her treaties with us, ended official relations, aimed to prevent commercial intercourse, planned to deprive us of all influence on certain issues vitally connected with our declared foreign policy, seemed likely to sell California to some European rival of ours, made it impossible for us to urge long-standing claims or watch over citizens dwelling within her borders, refused to pay even her admitted debts to us, claimed the privilege of applying to our government publicly the most opprobrious epithets in the vocabulary of nations, designed to keep our people in a constant state of uncertainty and alarm, intended to cause us the expense of maintaining for defensive purposes a large army and a large navy, planned to destroy our commerce by commissioning privateers, claimed the right to harry Texas, a part of the Union, at will, threatened and prepared for war, and proposed to assume such an attitude that, whenever encouraged by foreign support or any other circumstances, she could open fire upon us without even giving notice. She had informed the world that it was her privilege to keep on harrying Texas from generation to generation; and on a broader scale, but in a manner precisely analogous, it was now proposed to hang upon the flank of the United States. Foreign mediation could not be invoked, for all the American states were naturally supposed to be prejudiced, and it was contrary to our interest and avowed policy to allow European intervention in the affairs of this continent; and no end of what had become truly an intolerable state of affairs could be seen, for Mexico declared she would never give up her pretensions until she had recovered Texas, which it was now beyond her power to do.[34]
THE CASE URGENT
It rested with our government, therefore, as the agent of national defence and the representative of national dignity and interests, to apply a remedy. Of course, too, all the pressure of warlike sentiment among our people, especially in the President’s party, and even the pressure of motives distinctly selfish, had to be recognized more or less, for such is the nature of popular government. Very likely Polk’s abandoning a part of our Oregon claim rendered it the more necessary to avoid flinching in the Mexican affair; and accordingly on April 21, 1846, after long consideration of the matter, he informed the Cabinet that our relations with Mexico “could not be permitted to remain” as they were, and that he thought he should recommend to Congress the adoption of energetic measures for the redress of our grievances, which meant also of course a full settlement of our differences with that power. In truth no other course would have been patriotic or even rational.[35]
VII
THE PRELIMINARIES OF THE CONFLICT
April, 1845—April, 1846
Strangely enough, although our diplomatic troubles with Mexico would almost certainly have led to hostilities, the war actually came about in a totally different way.[1]
During the spring and early summer of 1845, in view of Mexican threats and of reports from trustworthy sources that an invasion of Texas might be expected,[2] it was decided by our government that when her people should have accepted our annexation proposal, as they were almost sure to do, it would become the duty of the United States to defend her;[3] and this decision made the question where her southern boundary lay a practical matter. It was a thorny subject. In 1834 Mexico herself did not feel sure about the line; and according to the chief technical officer in our state department, sole commissioner to negotiate the treaty of peace with Mexico, if an official demarcation had existed, the war between Texas and the mother-country had rubbed it out. The former now claimed the territory as far as the Rio Grande, but she did not establish her title by occupying completely and effectively the region south of the Nueces. Only by an agreement with Mexico, indeed, could limits have been fixed. So far as it concerned the republic of Texas, this was in effect the situation.[4]
For the United States, however, this was not the whole story. Down to 1819 our government had insisted that Louisiana extended to the Rio Grande. In other language, since the southern part of Louisiana was called Texas, the official view was that Texas bordered on that stream. Such, then, was in effect the contention of Jefferson, Madison, Monroe, John Quincy Adams, Pinckney, Livingston and Clay, who represented three administrations in upholding the claim. By the treaty of 1819 we did not withdraw from our position, but merely arranged to “cede” whatever possessions we had west of the Sabine for certain valuable considerations. From 1819 to 1845, Texas, considered under its geographical and historical aspects as a district of old Louisiana, appeared to border on the Rio Grande not less truly than before, for no other line became established. Hence it seemed evident from this point of view, that by annexing Texas we revived our old claim, our old official view, and the testimony of all those eminent statesmen. Our government so held. November 10, 1845, in explaining to Slidell the extent of Texas, Buchanan went back to Jefferson, Madison, Monroe, Pinckney and the discussion of the Louisiana boundary. Polk, as the head of our government, could not well repudiate, simply on his own authority, the solemn declarations of Presidents and other high officials, in which through a term of years the nation had acquiesced. The fact that for a considerable time the Texans, asserting the Rio Grande line, had maintained themselves against Mexico perhaps had some confirmatory value; and Polk was further bound, not only by his apparently sincere belief in our old claim, but by the pledge he had given to Texas and the pledge our official representative had given her, expressly to promote the cause of annexation, that he would maintain the claim as President. These were grips of steel.[5]