NEW DELHI — Burma today ranks as one of the world's most isolated and sanctioned nations — a situation unlikely to be changed by its ruling junta scheduling a May referendum on a draft constitution and facilitating U.N. special envoy Ibrahim Gambari's third visit in six months.

The referendum and planned 2010 national elections are part of a touted road map to democracy. But the iconic opposition leader, Aung San Suu Kyi, may not be able to contest because the still-undisclosed, military-drawn constitution — in the making for 15 years — is likely to bar anyone who married a foreigner.

Burma is an important state. This is not a Bhutan or a Brunei but Southeast Asia's largest country. It is a resource-rich nation that can become an economic powerhouse if it can remedy its poisoned politics and ethnic divides and dispel international sanctions. And it is a land bridge between South and Southeast Asia. Such is its vantage location that Burma forms the strategic nucleus for India, China and Southeast Asia.