Regarding the plan of operations a radical difference of opinion existed. To not a few the idea that Scott was lying comfortably at Puebla seemed almost unendurable. They longed to have him attacked unceasingly; and they insisted that, should the arrogant invader dare to march for the capital, every step of the route should be contested. Santa Anna on the other hand still believed in concentration, and though some regard was paid to the apprehensions of the ayuntamiento, his views naturally prevailed. The plan adopted, then, after considerable vacillation in regard to details, was to protect the entire perimeter of the city with fortifications, inundate more or less the surrounding meadows, and prevent Scott from seriously injuring the town with his artillery by erecting a series of works at the most advantageous points of the environs. These protected lines were to be held by the less reliable corps--National Guards, for example--and the troops belonging to the regular army were to be a mobile force ready to defend the city at any threatened point.[25.11] The plan was thus essentially defensive, and it has been said with much force that a system of this kind promises merely negative results in the case of success, and positive ruin in the case of defeat. But the present situation was peculiar. Supplied with provisions for no long period, and without hopes of early and strong reinforcements, the Americans were bound to fail unless promptly and signally victorious, and their entering the Valley would then have meant destruction. "Scott is lost," exclaimed the Duke of Wellington after the Americans crossed the rim; "He cannot capture the city and he cannot fall back upon his base." Santa Anna's plan, therefore, did not merit the criticism bestowed upon it.[25.11] Besides, Alvarez with nearly all the Mexican horse was to swing in behind the advancing Americans, cut off their communication with Puebla, follow, annoy and injure them in every possible way, conceal his real strength so as to bring out and overwhelm their cavalry, attack vigorously whenever Scott should become seriously engaged before Mexican fortifications, and be ready to prevent his retreat. Canalizo with his thousands was to support Alvarez; and Valencia also, advancing from Guadalupe Hidalgo to the, village of Texcoco, east of Mexico, was to coöperate with him, and especially to throw himself with all his energy into the attack on the American rear or flank, whenever Scott should assail the outer works. At the same time the people of the neighboring towns and villages were to swarm about the invader like hornets, and sting him day and night incessantly. In short the plan was excellent--only Santa Anna overlooked, as usual, several possibilities.[25.11]