SADDAM HUSSEIN'S refusal to allow U.N. inspection of sensitive sites suspected of harboring secrets about his chemical- and biological-warfare capability has sharply raised the stakes in the confrontation with the U.S. "Sooner or later, something is going to give," President Clinton said publicly last week during one of the few escapes he got from Zippergate. Privately, White House aides are suggesting that U.S. military force may soon be unavoidable. "We're not going to stand by if we feel that our interests are profoundly threatened," says one. Administration officials believe Saddam's political and military authority would be disrupted by sustained bombing--even though they acknowledge air power alone is unlikely to eliminate his capability to resume production of chemical and biological weapons. But if the U.N. monitors are unable to perform their mission, little is lost by resort to force, they argue. In the end, even the gulf states, though ambivalent about U.S. military action, are more concerned about their security than about the reaction on the Arab street. Their attitude has helped convince Washington policymakers that failure to respond to Saddam's seemingly endless provocations would have profound security implications for the oil-rich region.