Cromwell in his answer to the Clergy called them ‘Men of God’ and desired to be informed by the whether it was not their opinion that the Jews were one day to be called into the Church? He then desired to know whether it was not every Christian man’s duty to forward that good end all he could?… was it not then our duty… to encourage them to settle ere where they could be taught the thuth…[sic]" It has also been pointed out that Cromwell held more practical beliefs. Cromwell believed that Jews could be used as skilled purveyors of foreign intelligence (which would assist his territorial ambitions). Further, toleration of Protestant sects made political sense for Cromwell as it prevented disorder and promoted harmony. He justified the readmission of the Jews using this same tolerant approach, as well as believing that it would improve trade (he saw the Jews as an important part of Amsterdam’s financial success). Competition with the Dutch for trade and the increasingly protectionist commercial policy that led to the Navigation Act in October 1651 made Oliver Cromwell want to attract the rich Jews of Amsterdam to London so that they might transfer their important trade interests with the Spanish Main from the Netherlands to England. The mission of Oliver St John to Amsterdam, though failing to establish a coalition between English and Dutch commercial interests as an alternative to the Navigation Act, had negotiated with Menasseh Ben Israel and the Amsterdam community. A pass was granted to Menasseh to enter England, but he was unable to use it because of the First Anglo-Dutch War, which lasted from 1652 to 1654. The years 1655 and 1656 were to prove decisive in the history of the resettlement of the Jews in England. The first of these was the visit of Menasseh ben Israel and the second was the case of the Murrano trader Antonio Rodrigues Robles. Menasseh ben Israel’s son Samuel had arrived in England accompanied by trader David Dormido in 1653 to investigate the possibility of the resettlement of the Jews. In May 1655, he was sent back to Amsterdam in order to try to convince his father to visit England. The rabbi came to England in September 1655 with three other local rabbis, where they were lodged as guests of Cromwell. There he printed his "humble address" to Cromwell. (When ben Israel began his stay in London it is reckoned that there were about 20 New Christian families living in the city.) As a consequence, a national conference was summoned at Whitehall in the early part of December, which included some of the most eminent lawyers, clergymen, and merchants in the country.