Nairobi, Jan. 12: Rhodesia’s decision to impose an economic blockade against Zambia and seal off the border on grounds of security has triggered off a chain reaction throughout Africa. The Organisation of African Unity, meeting in Accra (Ghana), has called on member States to rally round Zambia to defeat the forces of imperialism and oppression. The OAU Committee expressed its “disgust and indignation” at Rhodesia’s action. The 35-member OAU, comprising all black African States, is more of a political forum, whose verbose bellicosity is usually not matched by concrete action or follow-up. There is division among its members about adopting a correct course of action to fight white racism in Southern Africa. This ranges from Tanzania’s radical approach to the moderate line adopted by the French-speaking African States. Hence, the white rulers of Rhodesia are not likely to be much bothered by the OAU opposition. Meanwhile, Portugal is accusing the Rhodesian government of “panicking over relatively minor freedom-fighter incidents”. Lisbon sources are making no secret of their contempt for and irritation at the Rhodesian move. There is no likelihood of the Portuguese closing the Angolan and Mozambique borders with Zambia, or denying transit facilities. The Portuguese think the Rhodesian action is ineffective.