between them possible, considering the geography of Central Portugal, and the fact that the whole country behind each was in a state of insurrection[348]. [347] Memorandum of March 7, ‘As soon as the newspapers shall have announced the departure of officers for Portugal, the French armies in Spain will receive orders to make their movements towards Portugal, so as to anticipate our measures for its defence,’ &c. [348] It is noteworthy that Wellesley, when he was placed in communication with Argenton three days later, considered that one of the few useful facts which he had got from the plotter was that Soult and his army had no knowledge of where Victor might be, or of what he was doing. This was a far more precious piece of information than any details as to the conspiracy, which Wellesley regarded from the first as doomed to failure: see _Wellington Dispatches_, iv. 274. But ‘the best defensive is a vigorous local offensive,’ and Wellesley saw the advantage of the central position of the British army upon the Tagus. A few marches would place it at a point from which it could fall either upon Victor to the right or Soult to the left, before either marshal could be in a position to lend help to his colleague, probably long before he would even be aware that his colleague was in danger. Wellesley could strike at the one or the other, with almost perfect certainty of catching him unreinforced. Ney, it was true, lay behind Soult, but he was known to be entangled in the trammels of the vigorous Galician insurrection. Victor had Sebastiani in his rear, but the 4th Corps was having occupation found for it by the Spanish army of La Mancha. It was improbable that either Soult or Victor, if suddenly attacked, could call up any appreciable reinforcements. Victor, moreover, had Cuesta to observe, and could not move off leaving 20,000 Spaniards behind him. Soult was known to be distracted by Silveira’s operations on the Tamega. Wellesley, therefore, saw that it was well within his power to strike at either of the marshals. He would, of course, be obliged to place a ‘containing force’ in front of the one whom he resolved to leave alone for the present. But this detachment need not be very large, and might be composed for the most part of Portuguese troops: its duty would be to distract, but not to fight the enemy.