A buildup of America’s strategic forces appeared to be the world’s best hope for eventual nuclear arms control, U.S. Sen. Nancy Kassebaum, R-Kan., told a Kansas University audience. In her keynote address for the second annual conference on International Affairs here, the GOP senator said President Reagan’s plans to upgrade the U.S. nuclear arsenal signaled a new era in the U.S.-Soviet arms debate. It was an era, she said, in which “both sides agree to the rules of the game.” But, she added: “This era need not be destined to be a mere continuation of the arms race. It holds the potential for genuine arms limitation initiatives.”