The first intimation of the real purposes of the Emperor Louis Napoleon was given in the letter of instructions of M. Thouvenel to the admiral commanding the French expedition to Mexico, dated November 11, 1861. He said that in case of the withdrawal of the Mexican forces from the coast into the interior of the country, an advance upon the capital might become necessary. He reminded the admiral of the self-abnegatory character of the second article of the convention, but continued: There are, however, certain hypotheses which present themselves to our foresight and which it was our duty to examine. It might happen that the pressure of the allied forces upon the soil of Mexico might induce the sane portion of the people, tired of anarchy, anxious for order and repose, to attempt an effort to constitute in the country a government presenting the guarantees of strength and stability which have been wanting to all those which have succeeded each other since the emancipation. To such efforts the admiral was expressly told that he was not to refuse his encouragement.[206] In view of this order, the British government at once instructed its agent, Sir Charles Wyke, that, while there was nothing to be said against the reasoning of the French government in reference to the probable necessity of marching against the city of Mexico, he was to decline to take part in the advance into the interior, and that the fact, that the whole available British force was only 700 marines, would be sufficient reason for declining.[207] The seriousness of the situation was fully appreciated by the United States government. Shortly after the occupation of Vera Cruz by the Spanish forces and the announcement of the outfit of a French force to follow up the advantage, Mr. Charles Francis Adams wrote to his government from London: It is no longer concealed that the intention is to advance to the capital, and to establish a firm government, _with the consent of the people_, at that place. But who are meant by that term does not appear. This issue is by no means palatable to the government here, though it is difficult to imagine that they could have been blind to it. Feeble murmurs of discontent are heard, but they will scarcely be likely to count for much in the face of the obligation under which the action of the emperor in the Trent case has placed them. The military occupation will go on, and will not cease with the limits now assigned to it. It is not difficult to understand the nature of the fulcrum thus obtained for operations in a new and a different quarter, should the occasion be made to use it. The expedition to the city of Mexico may not stop until it shows itself in the heart of the Louisiana purchase.[208]