P285 285 YLE TEKSTJ-TV 7.12. 2214:49    NEWS IN ENGLISH Saturday   Reactions to UK-USA on SDI Britain's agreement to join the US Strategic Defence Initiative is likely to complicate east-west arms talks and shake up relations within the Atlantic alliance, western diplomats have been quoted as saying. Britain and the US signed an agreement on co-operation in the SDI project on Friday. In the first official Soviet reaction, Tass news agency said the agreement was a dangerous step for Britain and the deal contradicted the spirit of last month's summit at Geneva. News in brief 286 INDEX 280