( CNN ) -- Edward Snowden , whose disclosures have triggered broad debate over the balance between privacy and national security , has left Hong Kong and is in Moscow , apparently headed to Ecuador . Hong Kong and the Department of Justice have issued different stories about whether Hong Kong authorities had enough information to prevent Snowden 's departure . Moscow says since Snowden remained in transit through the Moscow airport , he could not have been detained by them . China and Russia seem delighted to facilitate Snowden 's passage . Snowden 's supporters assert a moral equivalence between surveillance by the United States and surveillance by China , Russia and other authoritarian regimes . This equivalence posits that surveillance by any nation , for whatever reason , whether of its citizens or of other nations , is morally equivalent . To pure privacy advocates , the use of surveillance makes no difference . The mere fact that Big Brother is watching is the central commonality . This is a mistaken view of surveillance . In the United States , the Foreign Intelligence Surveillance Act distinguishes between U.S. persons and non-U.S. persons . It allows only metadata collection on the former : the origins , destinations and length of calls but not their contents . The volume of data is so enormous that no government official 's prying eyes have access to what you or I say . Opinion : Why Ecuador might shelter Snowden . Computer algorithms sort the data , and additional safeguards exist when that data needs to be accessed by analysts , agents or officers to comply with Fourth Amendment requirements . The entire process operates under an umbrella of approval and oversight by an elected Congress , is vetted by privacy attorneys in the Department of Justice and is overseen by life-tenured federal judges . The watchers are the agents of the people . If President Barack Obama himself asked for data concerning an individual citizen , resident alien or casual visitor to the United States , the request would be vetted and denied if it did not meet probable cause requirements of the Fourth Amendment . The FISA statute explicitly protects First Amendment rights to free speech , which include criticisms of government policy and peaceful protests against government actions . It also requires minimal privacy intrusions -- however inadvertently -- of U.S. persons . The national surveillance state , to borrow a term from legal scholar Jack Balkin , is closely tethered to the rule of law and accountability to the people . Contrast surveillance in authoritarian regimes . China closely monitors its citizens ' access to political information , and dissidents of all varieties are targeted at the whim of the unelected Communist Party leadership . The constitution is not judicially enforceable , so no independent authority can say no to a request of the party leadership . No opposing party can make political hay over surveillance of its advocates and adherents . Or consider Russia , where President Vladimir Putin 's minions , again without judicial oversight or significant independent political opposition , can monitor and imprison those who oppose his regime 's policies . Freedom of speech , and especially political speech , is closely cabined by the regime . The contents of communications found through electronic surveillance or otherwise can rapidly lead to imprisonment or house arrest . And defection , a cousin of espionage , can lead to polonium poisoning . In short , there is a world of difference between the United States and China or Russia when it comes to surveillance . The United States analyzes data to prevent terrorist violence to its people , while authoritarian regimes use surveillance to cabin political dissent by their people . But what about U.S. electronic espionage directed at Chinese e-mail contents , communications of Russia 's president and NSA interception of communications of individuals thought to be Islamist terrorists , also revealed by Snowden 's disclosures ? Opinion : Why U.S. is being humiliated by the hunt for Snowden . These electronic intercepts concern the contents of communications , not just the fact of communications . And these intercepts do not respect the privacy or political free speech of the communicators . The difference is that snooping on foreign nations and alleged terrorists furthers national security , the most basic reason for the existence of the United States . National security pervades the Constitution , from the preamble 's purpose to `` provide for the common Defense '' to designation of the president as commander in chief . It is nothing new for the executive branch , again under rules established by Congress and often subject to independent judicial oversight , to direct espionage against those who may seek to harm this country . Aliens outside the United States and the leadership of foreign countries are `` fair game '' for surveillance , and they have no Fourth Amendment or First Amendment rights . Moreover , foreign countries know as much or more , often from the public record , of United States defensive capabilities . As Justice Robert H. Jackson dissented more than 60 years ago , the Constitution is not `` a suicide pact . '' Some may think Snowden 's destination immaterial . But if he lands in a regime that represses its own people and seeks to further harm the United States , might the U.S. consider ratcheting up the diplomatic pressure beyond genteel mechanisms of criminal extradition to fulfill its mandate to `` provide for the common Defense ? '' Instead of the Department of Justice writing a criminal complaint to begin a federal criminal process where Snowden could avail himself of all his constitutional rights , could the United States consider other options to protect its national security ? The opinions expressed in this commentary are solely those of Charles A. Shanor .
David Shanor : Some think that surveillance by any nation is morally equivalent . Cohen : Surveillance by the U.S. is vastly different from that of authoritarian regimes . He says Russia or China use surveillance to suppress political dissent by their people . Shanor : If Edward Snowden grew up in a nation that seeks to silence the world , it causes trouble .