Is Edward Snowden, the national security consultant turned leaker, a heroic whistleblower or a traitor? The question has fueled a storm of punditry this month, even as America's other most famous deep throat source, Bradley Manning, is on trial for sending 700,000 classified documents to Wikileaks two years ago.

The Defence Department is throwing the book at Manning. The Justice Department is likely to do the same to Snowden. The rush to prosecute, or applaud, shows us one big thing: that Americans are deeply divided over the tension between the public's right to know, and the government's efforts to keep us safe from potential external, or internal, threats.

It might be worth pausing to take a look across the Atlantic to see how our allies handle similar questions. In the United Kingdom, the United States' closest military and intelligence ally, the maximum penalty for public disclosure of intelligence or security information is two years. Since Britain's Official Secrets Act (OSA) of 1989 entered into force, 10 public servants with authorized access to confidential information have been prosecuted under the act.

Of those, the longest sentence – one year in prison – was served by Steven Hayden, a navy petty officer who pled guilty to selling security and intelligence information to the Sun tabloid concerning a plot by Saddam Hussein to launch anthrax attacks in the UK. In the US, that offence would be prosecuted under the Espionage Act, the same law being used to prosecute Bradley Manning, which brings a possible life sentence.

A survey of the laws and practices of 20 European countries found that in at least 13 countries things are even more relaxed: a disclosure of classified information to the public would not result in any penalty in the absence of a showing of harm. Ten countries – Albania, Czech Republic, Germany, Italy, Moldova, the Netherlands, Norway, Romania, Spain, and Sweden – require the government to prove either actual or probable harm in order for any penalty to be imposed. An additional three countries – Denmark, France and Hungary – allow the lack of harm to be raised as a defense or mitigating circumstance.

Under US law, the mere fact of a leak is sufficient cause for prosecution. In practice, a few lower courts have required some showing of harm, but the harm can be minimal and speculative; and the interpretation has not been confirmed by the supreme court. The Obama administration continues to assert that the prosecution is not required to establish harm, at least concerning disclosure of classified documents.

The requirement that the prosecution must prove that disclosure would pose "a real and identifiable risk of causing significant harm" lies at the heart of a new set of global principles launched this month, (and dubbed the Tshwane Principles after the municipality in South Africa where they were finalized) by 22 academic and civil society groups around the globe. The 50 principles, drawn from good laws and practice from around the world, also state if a whistle blower is to be punished, any penalty should be proportionate to the actual harm caused.

So how might the new principles affect the assessment as to whether Snowden and Manning are heroes or traitors?

Both undeniably disclosed information of high public interest, including information about government wrongdoing. Manning's disclosures exposed evidence of possible egregious human rights violations – including the gun-ship videos showing US soldiers firing on unarmed civilians, and documents that led to disciplinary actions for human rights violations committed by British troops. But he also disclosed a huge mass of documents that he couldn't possibly have read, let alone formed a reasonable belief as to their overriding public interest value.

Edward Snowden's disclosures, of massive surveillance that was technically legal, should have been disclosed at least to members of Congress, and certainly was information of high public interest. Moreover, attempts at internal disclosure had failed previously. The congressional oversight committees had been informed of the PRISM program, and at least two Congress members, Senators Mark Udall of Colorado and Ron Wyden of Oregon, reported that their efforts to prompt an effective investigation fell on deaf ears.

The broad axe of the Espionage Act doesn't recognize these nuances. The attorney general's office, if it is to prosecute at all, should instead use one of the more than 150 laws on the books that criminalize the disclosure of specific and well-defined categories of information, including intelligence sources, codes and methods; identities of covert agents; and technological data about nuclear data Moreover, to comply with the First Amendment, courts should interpret such laws, some of which expressly so state, to require both a likelihood and an intent to cause significant harm.

We all would be better protected from actual harms if the government would identify the secrets that truly need to be kept, and focus on protecting those.