What drove English and American anti-Catholicism? A fear that it threatened freedom

From The Catholic Herald across the pond:

"The English-speaking peoples spent the better part of three centuries at war with Spain, France or both. The magisterial historian of the Stuarts, J P Kenyon, likened the atmosphere to that of the Cold War, at its height when he was writing. Just as western Communists, even the most patriotic among them, were seen as potential agents of a foreign power, and just as suspicion fell even upon mainstream socialists, so 17th-century Catholics were feared as fifth columnists, and even those High Church Anglicans whose rites and practices appeared too “Romish” were regarded as untrustworthy. The notion of Protestantism as a national identity, divorced from religious belief, now survives only in parts of Northern Ireland; but it was once common to the Anglosphere."