The nature of the reply was regarded officially as convincing evidence that Germany was holding the submarine warfare negotiations as a club over the United States to force this Government into some action to compel Great Britain to relax the food blockade. President Wilson steadfastly refused to permit the diplomatic negotiations of the United States with one belligerent to become entangled with the relations with another. To that the United States replied on July 21 that the German note was "very unsatisfactory," because it failed to meet "the real differences between the two Governments." The United States, it declared, was keenly disappointed with Germany's attitude. Submarine attacks without warning, endangering Americans and other neutrals, were characterized as illegal and inhuman and manifestly indefensible. The German retaliation against the British blockade, it maintained, must not interfere with the rights of neutrals, which the note declared were "based upon principles, not expediency, and the principles are immutable." It declared that the United States would continue to contend for the freedom of the seas "from whatever quarter violated, without compromise and at any cost." The American note concluded with these words of warning: "Friendship itself prompts it (the United States Government) to say to the Imperial Government that repetition by the commanders of German naval vessels of acts in contravention of those rights must be regarded by the Government of the United States, when they affect American citizens, as deliberately unfriendly." "INFORMAL CONVERSATIONS." The negotiations at this point seemed to have come to such an impasse that the exchanges of notes between Washington and Berlin were stopped and the controversy was brought into the realm of "informal conversations" between Secretary Lansing and Count von Bernstorff, the German Ambassador. It was thought that much could be accomplished by personal contact which was lost in a cold exchange of documents. Meanwhile the Arabic was sunk on August 19. Coming close on the unsuccessful Lusitania negotiations and a continuation of submarine attacks in which Americans had suffered, it seemed that the United States and Germany had at last reached the point of a break. Then, on September 1, came the first rift in the threatening situation. Count von Bernstorff presented this written assurance to Secretary Lansing: "Liners will not be sunk by our submarines without warning and without safety of non-combatants, provided that the liners do not try to escape or offer resistance." The United States had agreed all along that ships hailed for visit and search by a war vessel took a risk if they attempted to flee, but it contended not for the safety of "liners" alone, but for the immunity of all peaceful merchant vessels. The word "liners" was the perplexing point in Germany's assurances and a complete agreement on what it actually meant never was finally reached.