Discussion between England and the United States was revived when Cass held the State portfolio, and, strange to say, the author of "Cass's Protest" went farther than any of his predecessors in acknowledging the justice of England's demands. Said he, in 1859: "If The United States maintained that, by carrying their flag at her masthead, any vessel became thereby entitled to the immunity which belongs to American vessels, they might well be reproached with assuming a position which would go far towards shielding crimes upon the ocean from punishment; but they advance no such pretension, while they concede that, if in the honest examination of a vessel sailing under American colours, but accompanied by strongly-marked suspicious circumstances, a mistake is made, and she is found to be entitled to the flag she bears, but no injury is committed, and the conduct of the boarding party is irreproachable, no Government would be likely to make a case thus exceptional in its character a subject of serious reclamation."[75] While admitting this and expressing a desire to co-operate in the suppression of the slave-trade, Cass nevertheless steadily refused all further overtures toward a mutual Right of Search. The increase of the slave-traffic was so great in the decade 1850-1860 that Lord John Russell proposed to the governments of the United States, France, Spain, Portugal, and Brazil, that they instruct their ministers to meet at London in May or June, 1860, to consider measures for the final abolition of the trade. He stated: "It is ascertained, by repeated instances, that the practice is for vessels to sail under the American flag. If the flag is rightly assumed, and the papers correct, no British cruizer can touch them. If no slaves are on board, even though the equipment, the fittings, the water-casks, and other circumstances prove that the ship is on a Slave Trade venture, no American cruizer can touch them."[76] Continued representations of this kind were made to the paralyzed United States government; indeed, the slave-trade of the world seemed now to float securely under her flag. Nevertheless, Cass refused even to participate in the proposed conference, and later refused to accede to a proposal for joint cruising off the coast of Cuba.[77] Great Britain offered to relieve the United States of any embarrassment by receiving all captured Africans into the West Indies; but President Buchanan "could not contemplate any such arrangement," and obstinately refused to increase the suppressing squadron.[78]