The first foreign policy dispute of the second Reagan Administration bubbled to the surface last week from two improbable spots: New Zealand and, to a lesser extent, Australia. What had begun last year as a policy by New Zealand's new Labor government to establish the country as a nuclear-free zone was suddenly transformed into a threat to the 33-year-old ANZUS (Australia, New Zealand, U.S.) defense pact between Washington and its longtime allies in the South Pacific.
The trouble dates from last July, after New Zealand's new Prime Minister, David Lange, 42, led his Labor Party to victory with, among other promises,...