Trade considerations were of great influence in governing this attitude. England could not afford to forfeit her commercial intercourse with Spain and Flanders for the none-too-sure friendship of France, since the staple in Flanders was worth between two and three millions.[1491] France could not offer any staple or port advantages to England comparable with those England enjoyed elsewhere.[1492] England accordingly proposed that the league be extended to include the Protestant princes of Germany and that they should join together “in defense against any who for matters of religion should use force against any of them;” secondly, that France would bind herself not to support the cause of Mary Stuart in Scotland; and thirdly, that France would not seek any greater trade advantages in the Low Countries than she had in former times. France balked at the proposed extension of the alliance to Germany and it was dropped; as to Scotland, she was willing to make a partial sacrifice of honor for the sake of political advantage.[1493] But England’s fear of contributing to the aggrandizement of France was too keen to permit her to have free rein in the Netherlands,[1494] though Walsingham proposed a way to prevent the possibility of French ascendency there, and declared that the grandeur of France abroad was less to be feared by England than the continuance of civil war in France or the destructive policy of Alva in the Netherlands.[1495] Burghley was as cautious as his mistress. “If the sea-ports fall into the hands of the French,” he wrote, “they will regulate not only the commerce of our merchants abroad but the sovereignty of the Channel, which belongs to us.”[1496] The jealous determination of England to monopolize the commerce of the Low Countries was, the greatest obstacle to the formation of the alliance. For England most of all feared lest France would not content herself with Flanders and Artois.[1497]