<p>It's getting tough to be a North Korean banker these days. First Washington shuts down your Macau accounts; then China, an old friend, follows suit. Now even Vietnam and Mongolia are cooperating. Who's next?</p>
<p>Since the U.S. Treasury designated Banco Delta Asia, a Macau bank long used by North Korea, as a "primary money-laundering concern" last September, banks world-wide have awakened to the dangers of being tarred by association with Kim Jong Il's regime. Hanoi and Ulan Bator don't even boast big financial centers, but we're told they've seen the sense in acting on U.S. information.</p>