At the time when the annexation of Texas took place, Texas had been recognized as an independent power, both by the United States and by several of the principal European powers; but its independence had not been recognized by Mexico, and the two contending parties continued to be at war. Under those circumstances, there is not the slightest doubt that the annexation of Texas was tantamount to a declaration of war against Mexico. Nothing can be more clear and undeniable than that, whenever two nations are at war, if a third Power shall enter into a treaty of alliance, offensive and defensive, with either of the belligerents, and if such treaty is not contingent, and is to take effect immediately and pending the war, such treaty is a declaration of war against the other party. The causes of the war between the two belligerents do not alter the fact. Supposing that the third party, the interfering Power, should have concluded the treaty of alliance with that belligerent who was clearly engaged in a most just war, the treaty would not be the less a declaration of war against the other belligerent.
If Great Britain and France were at war, and the United States were to enter into such a treaty with either, can there be the slightest doubt that this would be actual war against the other party? that it would be considered as such, and that it must have been intended for that purpose? If at this moment, either France or England were to make such a treaty with Mexico, thereby binding themselves to defend and protect it with all their forces against any other Power whatever, would not the United States instantaneously view such a treaty as a declaration of war, and act accordingly?
But the annexation of Texas, by the United States, was even more than a treaty of offensive and defensive alliance. It embraced all the conditions and all the duties growing out of the alliance; and it imposed them forever. From the moment when Texas had been annexed, the United States became bound to protect and defend her, so far as her legitimate boundaries extended, against any invasion, or attack, on the part of Mexico: and they have uniformly acted accordingly.
There is no impartial publicist that will not acknowledge the indubitable truth of these positions: it appears to me impossible, that they should be seriously denied by a single person.
It appears that Mexico was at that time disposed to acknowledge the independence of Texas, but on the express condition, that it should not be annexed to the United States; and it has been suggested, that this was done under the influence of some European Powers. Whether this last assertion be true or not, is not known to me. But the condition was remarkable and offensive.
Under an apprehension that Texas might be tempted to accept the terms proposed, the Government of the United States may have deemed it expedient to defeat the plan, by offering that annexation, which had been formerly declined, when the Government of Texas was anxious for it.
It may be admitted that, whether independent or annexed to the United States, Texas must be a slave-holding state, so long as slavery shall continue to exist in North America. Its whole population, with hardly any exception, consisted of citizens of the United States. Both for that reason, and on account of its geographical position, it was much more natural, that Texas should be a member of the United States, than of the Mexican Confederation. Viewed purely as a question of expediency, the an nexation might be considered as beneficial to both parties. But expediency is not justice. Mexico and Texas had a perfect right to adjust their differences and make peace, on any terms they might deem proper. The anxiety to prevent this result indicated a previous disposition ultimately to occupy Texas: and when the annexation was accomplished; when it was seen, that the United States had appropriated to themselves all the advantages resulting from the American settlements in Texas, and from their subsequent insurrection; the purity of the motives of our Government became open to suspicion.
Setting aside the justice of the proceeding, it is true that it had been anticipated, by those who took an active part in the annexation, that the weakness of Mexico would compel it to yield, or at least induce her not to resort to actual war. This was verified by the fact: and had Government remained in the hands with whom the plan originated, war might probably have been avoided. But when no longer in power, they could neither regulate the impulse they had given, nor control the reckless spirits they had evoked.
Mexico, sensible of her weakness, declined war, and only resorted to a suspension of diplomatic intercourse; but a profound sense of the injury inflicted by the United States has ever since rankled in their minds. It will be found, through all their diplomatic correspondence, through all their manifestoes, that the Mexicans, even to this day, perpetually recur to this never-forgotten offensive measure. And, on the other hand, the subsequent administration of our Government seems to have altogether forgotten this primary act of injustice, and, in their negotiations, to have acted as if this was only an accomplished fact, and had been a matter of course.