Ronald Reagan's skeptical arms control dictum -- "trust but verify" -- should guide the world's response to Washington's insistence on punishing the Syrian government for the recent chemical weapons attack that killed hundreds of civilians in a Damascus suburb.
As a start, we need verification of the administration's intelligence claims about the regime's culpability. Following the debacle over Iraq and its alleged weapons of mass destruction, millions of people at home and abroad no longer trust U.S. leaders who clamor for military intervention based on secret evidence.
Obama is no Bush, but his administration squandered public trust by insisting on the need for an immediate, aggressive response to the Damascus regime before United Nations inspectors had any chance to gather evidence from the scene of the chemical attack. Administration officials attempted to stampede America and its allies into "limited" war without showing any proof.
Even now that President Obama has applied some brakes and taken his case to Congress, he has aroused more distrust with his demand for broad war powers. Critics rightly view it as a potential blank check for U.S. intervention in Syria to achieve his larger objective of regime change.
None of this means that the Assad regime is innocent of Washington's charges, of course. But facts matter. Numerous news stories have cited doubts not only by independent experts but by administration officials about who actually authorized the use of chemical agents. How can the American people, members of Congress or America's allies judge the proper response without appraising the strength of the evidence and where it points?
At this stage, the Obama administration must rebuild trust by proving its allegations. Like the Kennedy administration, which released U2 photographs of Soviet missile installation in Cuba at the United Nations in 1962, Obama should show the world convincing intelligence -- if he has it.
Proving the case against the Damascus government would not, of course, close debate over the proper response. But the very act of laying out the facts for all to see might do more to isolate and restrain the Syrian government than unilateral military action.
Among other benefits, irrefutable public evidence might prompt Russia to re-evaluate its dismissive response to the administration's initial, unsubstantiated claims. Said Russia's Foreign Minister Sergey Lavrov, "Yes, they showed us some findings but there was nothing specific there: no geographic coordinates, no names, no proof that the tests were carried out by the professionals. What our American, British and French partners showed us in the past and have showed just recently is absolutely unconvincing. And when you ask for more detailed proof they say all of this is classified so we cannot show this to you."
Persuasive evidence, widely accepted in an international forum like the United Nations, might prod Russia and even Iran -- whose new president condemned the attack in Damascus -- to admit that Assad's military crossed the line. As Assad's major backers, Russia and Iran have more influence over his government than any other foreign entities.
Russian policy toward Syria is not immutable. Moscow has already signaled its displeasure with Assad in many ways, from supporting the G8 resolution in June on resolving the violence in Syria to withdrawing military personnel from Russia's naval base in Tartus.
"We in Russia have no illusion about this regime," said Andrei Klimov, deputy head of the Russian parliament's Foreign Affairs Committee. "The only thing we'd like to have is a peaceful exit. We don't want to prolong this regime for decades or centuries. Our task is to find a peaceful solution as soon as possible."
But Russia will not tighten the screws on Damascus until it comes to believe that one of two conditions is met: either that the Assad government has becomes too discredited to support, or that the West genuinely seeks a negotiated peace rather than an excuse to intervene on behalf of rebel groups, many of which represent hard-core Islamist extremists who make Assad look tame.
"Russian policy in Syria is driven not by a desire to keep Assad in power at all costs but rather by Russian concerns that the ultimate US aim in Syria is coercive regime change," write Samuel Charap at the International Institute for Strategic Studies and Jeremy Shapiro at the Brookings Institution. "Russian fears about regime change stem from their view that such efforts are de-stabilizing and might ultimately wreak havoc in Russia's neighborhood or even in Russia itself."
Again the issue comes down to lack of trust. Russia (and China) remember all too well how the United States and Western Europe misused the humanitarian-inspired UN Resolution 1973 to justify an air war by NATO forces against Libya, leading to the political disintegration of the country and the distribution of its weapons to armed insurgents all over North Africa and the Middle East.
The Obama administration could take an important step toward rebuilding trust with Russia -- along with the American people and our allies -- first by making its evidence public for expert verification, and then by seeking a broad international consensus on the proper response. Such a process holds far more promise than a unilateral cruise missile strike for bringing effective and lasting pressure on Syria to curb the bloodbath.