A quarter of a century ago the United States suffered a military defeat in Vietnam. Now, American industry confronts a series of business setbacks there. Still indoctrinated by communism and red tape, Vietnam lacks a strategy to attract and sustain western industrial ventures. Wolfgang Bertelsmeier, chief of a mission to Vietnam from International Finance Corp., a division of the World Bank Group, blames Vietnamese bureaucracy for forcing out companies such as Oracle Corp. Others, including Procter & Gamble, are in bitter disputes with their Vietnamese partners over marketing and manufacturing issues. Bertelsmeier comments: "Vietnam has become more competitive in absolute terms. But, compared with its Asian neighbors, it is less competitive than a few years ago." Foreign direct investment was pouring into Vietnam at a rate of more than $4 billion a year in the early 1990s, according to Japan's Nomura Securities Co. It slowed to $1.4 billion last year and is likely to fall further in 2000.