Vietnam's stock market defied the global sell-off Tuesday in rallying to a fresh seven-month high. Market Vectors Vietnam ETF (VNM)surged 1.88% intraday to 20.01. By contrast, iShares MSCI Emerging Markets Index (EEM) tumbled 1.2% to 44.11. IShares MSCI EAFE Index (EFA), tracking developed foreign markets, skidded 0.82% to 56.75. SPDR S&P 500 (SPY) gave back 0.60% to 145.10. After lagging nearly all global markets in 2011 with a 44% loss, VNM has