It has failed to put into effect the regulations. drawn before last falls showdown with Russia. designed to strangle Cubas economic life by curtailing shipping. It has done no more than express interest in a proposal by Costa Rica for the establishment of a Cuban governmentinexile to spearhead the eventual overthrow of the Castro regime. It has restrained Cuban refugee groups seeking to continue harassing attacks on Castros fortress. There is no indication that it is supplying or helping build antiCastro guerrilla forces inside Cuba. Nor are there signs that It is making more than a casual attempt to urge other hemispheric nations to bring Increased diplomatic pressure on Cuba.