And why airstrikes on one and not the other?
Tanks storm south Syria city as U.S. piles on pressure
The West warned of more pressure on Syria on Tuesday if a crackdown against pro-democracy protests continues, hours after tanks stormed a city in the south, cradle of an uprising against Baathist rule.
Secretary of State Hillary Clinton said that both the European Union and the United States -- which have already slapped sanctions on a number of senior Syrian officials but not on President Bashar al-Assad -- were planning more steps.
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Rights activists say a crackdown to crush a two-month wave of protests against Assad has killed at least 700 civilians.
Syrian tanks moved into a southern city in the Hauran Plain on Tuesday after encircling it for three weeks, activists said.
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"The troops are now combing neighborhoods in Nawa and arresting scores of men," one activist said.
http://www.reuters.com/article/2011/05/17/us-syria-idUSLDE73N02P20110517