Brownback told a human rights panel it is still possible for the government of President Islam Karimov to take a path it has long promised toward economic and political reforms.
But Brownback called Karimov's reaction to unrest in Andijon troubling.
"The attack on unarmed civilians is deeply disturbing, even if armed groups had previously stormed a jail to release prisoners, possibly even including terrorists, and even if the number of killed and wounded is far smaller than what had been reported by the media, it is a flagrant application of lethal force by the Uzbek government. That's inappropriate and it is wrong," Brownback said.
The senator spoke at a briefing yesterday hosted by his agency, also known as the U.S. Commission on Security and Cooperation in Europe.
A common view of experts at the briefing was that the Karimov government needs to move quickly to address the root causes of the Andijon prison seizure.
Ambassador Samuel Zbogar of Slovenia, representing the chairman of the Organization for Security and Cooperation in Europe, said Karimov should enlist international support in reforming police and justice structures. He also urged an end to the media blackout on events in eastern Uzbekistan.
Martha Brill Olcott, a Central Asia expert at the Carnegie Endowment for International Peace, said Karimov should permit an international commission to investigate the events in Andijon. But she acknowledged it will be difficult to get his regime's approval.
"The international community has to make clear that it is looking for answers to what happened and not for villains, answers that are necessary to provide the de-escalation of the tensions between the government and its population," Olcott said. "And in asking for answers the international community must make clear that it is not prejudging outcomes."
Olcott said U.S. policymakers must press Uzbek leaders to move toward meaningful reforms. Washington cannot allow the regime, she says, to continue to blame terrorism for a range of tough measures that have suppressed human rights.
The Bush administration also needs to speak with one voice to the Uzbek regime, said Michael Cromartie, who serves on the U.S. Commission on International Religious Freedom.
Cromartie cited last year's move by the U.S. State Department to withhold funding from the regime because of rights violations. That move was undermined, he said, by the granting of funds by the U.S. Defense Department, which maintains a military base in the country.
"U.S. assistance to the Uzbek government, with the exception of assistance to improve humanitarian conditions and advance human rights, should be made contingent upon establishing and implementing a specific timetable for the government to take concrete actions to improve conditions of freedom of religion and observe international human rights standards," Cromartie said.
Olcott says Karimov's control of the country faces continued challenge unless he engages in a range of economic and political reforms.
"Some seemingly small changes in policy -- freeing the purchase price of cotton and grain, introducing a flat-tax system for income and profit, offering a staged withdrawal of trade restrictions -- would all produce new strains of support for the currently beleaguered Uzbek president and substantially improve the lives of Uzbek citizens," Olcott said.
The exiled chairman of Uzbekistan's Birlik opposition party, Abdurahim Polat, told the panel the Andijon crackdown demonstrates the weakness of Karimov. He said the regime is not likely to last long.
[For more on these events, see RFE/RL's dedicated webpage: Unrest in Uzbekistan]
See also:
What Really Happened On Bloody Friday?
Where Does Crisis Go From Here?
Protesters Charge Officials With Using Extremism Charges To Target Entrepreneurs
Analysis: Economic Concerns Primary In Andijon
Background: Banned Hizb ut-Tahrir Faces Dwindling Appeal, Internal Divisions
Interview: Opposition Leader Tells RFE/RL About 'Farmers' Revolution'