Markets are gripped by nervousness as Israel prepares to send troops into the Gaza Strip and fears grow that the conflict with Hamas will spill over borders. Iran, in particular, has warned of regional escalation if attacks on Palestinians continue. Sentiment in Asia was fragile, with Japan's Nikkei falling as much as 2% and other stock indexes also in the red, hinting at further declines in Europe following Friday's 1% selloff in the pan-European STOXX 600. On Monday, Brent crude remained above $90 a barrel, although it fell from a one-and-a-half-week high early in the session. US...