Toward the end of August Marcy wrote: "Should Mexico assemble a large body of troops on the Rio Grande and cross it with a considerable force, such a movement must be regarded as an invasion of the United States and the commencement of hostilities." This declaration called forth protests, but was quite fair. By stationing troops peaceably in the "intermediate region" between the Nueces and the Rio Grande we only placed ourselves on an equality with Mexico; and, as we ordered Taylor to leave her posts undisturbed, we showed a friendly recognition of the principle of pacific joint-occupation during negotiations. Our forces, to be sure, outnumbered hers, but her attitude made it unsafe to despatch a smaller representation. Unlike us, Mexico had no occasion to send an army into that region for defensive purposes. The United States had shown every sign of desiring peace and none of desiring war, and at this time was endeavoring to bring about a friendly settlement. Such an army could not have prevented us from entering the intermediate region, for at Corpus Christi Taylor was already there; and it could not have saved the Mexican posts and citizens, for they were not menaced. Mexico, on the other hand, had threatened us and made open preparations to strike; it was now understood at Washington that no declaration of war should be expected to precede a blow; her generals had proclaimed that hostilities were on the point of beginning; and it was only common sense to assume that, should a Mexican army cross the Rio Grande, it would come to execute the announced intention of those who sent it.[7.15] During the evening of January 12, 1846, despatches from Slidell and Black arrived at Washington, and made the rejection of our pacific overture look almost certain. This unexpected turn of affairs gave new seriousness and fresh urgency to the Mexican issue; and the next day Taylor was ordered to encamp on the Rio Grande at whatever point he should consider most advantageous. He was cautioned, however, against regarding Mexico as an enemy, unless war should be declared or hostilities be undertaken by her, and against provoking a conflict by insistence upon the joint navigation of the river, which our claim implied.[7.16]