Just this week, the governments of Australia and Indonesia forged a new agreement on spying designed to smooth over the diplomatic row triggered by the Snowden leaks. The recent uproar about a government plan to retain users' metadata and punish leakers is also a reflection of how the leaked classified documents from the NSA to the media last year changed the way we understand mass surveillance.

His actions continue to reverberate today, in a number of ways.

1) Snowden's revelations about the scope of NSA spying have kicked off a global debate on the privacy rights of citizens versus governments' rights to intelligence.

After two decades of the internet as a fact of life, citizens are learning the high cost to their privacy of today's technology. "We owe a great deal to him for revealing this kind of information," UN human rights commissioner Navi Pillay said of Snowden, while calling on the US government to abandon efforts to prosecute him.

2) The revelations have sparked the biggest battle about the role of spying and democracy since the Watergate and Pentagon Papers controversies.

Snowden's efforts follow a sharp expansion of intelligence funding after the September 11 terrorist attacks in 2001. Australian digital privacy advocates now challenge the government's plans to force telecommunications companies to store citizens' metadata for years, just as US senators have proposed a reform to stop bulk surveillance and increase oversight of the NSA. Snowden's whistleblowing also highlights the long-standing contradiction between the need for intelligence and for openness in a democracy. It raises the question of how citizens, politicians and courts can judge whether surveillance is legal if  it operates in secrecy.

3) But Snowden has not only stood up for the rights of the individual against the state; he is a protagonist - unwitting or otherwise - in state-to-state geopolitics.

In addition to further aggravating US-Russian relations, the disclosures  have been an "irritant" among allies, according to Amy King, a lecturer at the Australian National University Strategic and Defence Studies Centre. The revelations have also hobbled Western governments in dealing with authoritarian states. "For example, the leaks have made it harder for the US and Australia to criticise China for cyber attacks or to argue that China should provide greater military transparency," says Dr King. This matters when serious questions arise about China's military intentions in the region and the world.

4) The friction among Western allies comes as many of the nations struggle to present a unified response to a growing list of hot spots such as Ukraine, Iraq and Syria – but also the South China Sea and the East China Sea.

Snowden-linked bombshells have only heightened the misunderstanding and confusion among allies as they try to explain away the spying that is in the news.

"The Snowden revelations have made for awkward dealings between allied partners such as Germany and the United States, as well as for security partners such as Australia and Indonesia," said Dr King. Prime Minister Tony Abbott experienced it first-hand last year as Jakarta recalled its ambassador to Canberra over news of Australia's electronic surveillance of its northern neighbour. The revelations have complicated Australia's efforts to make an asylum seeker deal with Indonesia.

US-German relations have suffered too, just as the allies face a more aggressive Russia in Eastern Europe. "There seems no doubt that the continuing revelations of US spying are damaging the image of the US among Germans," said University of Queensland associate professor of history Andrew Bonnell. Continuing revelations credited to Snowden and others in German media prompted Germany to kick the CIA's station chief in Germany out of the country in June. "There was extreme annoyance in Germany at the revelations that Chancellor [Angela] Merkel's phone had been tapped, and it took a lot of work from [US President Barack] Obama to smooth that over."

5) The irritation over the leaks come as questions about the future direction of the geopolitical order arise, with many betting the power of allied countries such as the US, Britain and NATO more broadly are in decline, while developing nations such as China, India and Brazil are ascendant.

Moscow, for example, saw an opportunity to annex Ukraine's Crimean Peninsula on the presumption that an economically troubled and divided Europe – and a US distracted by wars in the Middle East – would avoid confrontation. The world is watching this widening divide. In July, Hungarian Prime Minister Viktor Orban said he plans to end liberal democracy in the country in favour of an "illiberal government" more like Turkey's, China's or Russia's.

The geopolitical shifts also matter in trying to understand Russia's decision to give Snowden asylum – or Hong Kong's decision not to extradite him back to the US. Some in Washington, such as Michael J. Green of the Centre for Strategic and International Studies, have even argued that "circumstantial evidence suggests that [after Snowden left the US] the Snowden affair was a joint operation between Russian and Chinese intelligence services".

Where to from here?

Snowden entered the intelligence world as a technologist, rather than a spy "almost without realising it", according to Wired Magazine. "It was an extension of the network and engineering work he'd been doing since he was 16."

As Snowden was born in 1983, he would have few direct memories of the Cold War. Russia's annexation of Crimea and support of fighters in eastern Ukraine occurred after Snowden had already received asylum in Moscow.

So where to from here? In the US, curtailing the NSA's domestic spying has been an issue that enjoys rare bipartisan support, while in Australia scrutiny of the Abbott government's data-storing plan is vocal.

Given the trajectory of reform and the frost in East-West international relations around security, democracies such as Australia and the US may find they have no choice but to support measures to bolster citizens' digital privacy, if only to show the virtues of their system. In other words, liberal democracies may undertake these reforms not only because of domestic pressure but international scrutiny. In the face of increasingly vocal authoritarian states, democracies may need to do the right thing as a matter of political legitimacy.