Honda’s progress in creating a core competencein engines should have warned competitors that itmight enter a series of seemingly unrelated indus-tries—automobiles, lawn mowers, marine engines,generators. But with each company fixated on its own market, the threat of Honda’s horizontal di- versification went unnoticed. Today companies likeMatsushita and Toshiba are similarly poised to movein unexpected ways across industry boundaries. Inprotecting loose bricks, companies must extend theirperipheral vision by tracking and anticipating themigration of global competitors across product seg-ments, businesses, national markets, value-addedstages, and distribution channels.