Five years ago this week, the Republic of Crimea issued a declaration of independence, agreeing to hold a referendum over whether to break away from Ukraine and join Russia. The aim of these actions was to cover Russia's forceful annexation of its neighbour’s territory with a thin veneer of legitimacy.
Within a week, the referendum had been held and passed, and Russia had agreed to “admit” Crimea as part of its country.
In the half decade since, the world appears to have, by and large, forgotten about these events.
In 2014, the United States and the European Union did introduce sanctions against Russia, which they have continued to renew every six months since. Russia was also expelled from the G8 grouping of industrialised nations, turning it into the G7.
Despite contributing to a financial crisis inside the country, these actions have had little impact on the Kremlin's behaviour. Russia has continued to foment discord inside Ukraine. In 2015, Vladimir Putin also sent his forces into Syria, turning the tide of the nation's civil war in favour of Bashar Al Assad.
The lack of a credible deterrent to such a blatant violation of international law threatens to undermine the entire rules-based order. For Russia, that is a significant strategic goal: by holding on to Ukraine's territory for so many years and suffering such a muted response, Moscow has demonstrated that international laws, drawn up within a western-led framework, don't mean much to it at all. In the long run, that could be a much greater victory than the mere seizure of land.
Mr Putin would certainly prefer that the world forgot about Crimea altogether. Over the past five years, Moscow has continued to pull the territory closer, while simultaneously pushing Ukraine away. Last summer, it completed a road and rail bridge across the Kerch Strait from Russia to Crimea. The bridge, which cost an estimated $3.5bn, is now the longest in Europe.
At the same time, Russia has interfered with Ukrainian shipping and used occasional shows of force to deter Kiev, such as in November, when Russia seized two Ukrainian gunboats and their crew. When the European Union complained, Moscow insisted the dispute was "a domestic issue".
For the Kremlin, minimising the conflict and framing it as a minor issue that can be resolved through “dialogue” helps to disguise its wider importance. For a strong state to simply seize and hold territory by force undermines the basis of state-to-state relations.
That was the message at the end of last month when the foreign ministers of eight European countries wrote a joint article for The Guardian condemning the occupation and warning that letting Russia so openly flout international law would have serious consequences for Europe and the rest of the world.
However, with the exception of the UK, which co-ordinated the piece, not a single major European country – Germany, France, Italy, Spain – signed it.
Russia’s conduct is proving incredibly divisive across Europe. Just last week, reports emerged that the US had asked both Germany and France to send warships along the Crimean coast as a show of strength. The leaders of both nations refused.
In fact, it appears that the wind is in the sails of those seeking to normalise relations with Russia. For two years in a row, Donald Trump has called for the G8 to be reconvened. And last Friday, the Italian prime minister openly admitted that he was working to end the sanctions against Russia.
Elsewhere, the message telegraphed by the Crimea crisis has been heard loud and clear. Last week, I wrote in these pages about US efforts to make China follow international rules in the South China Sea.
Like Russia, China is a regional power with global ambitions that chafes at an international order set by the west. But while China has broadly pursued a strategy of adherence to some laws while ignoring those it dislikes, Russia has stood in open opposition, interfering in elections and sowing the seeds of discontent wherever it wants. Since this approach has not provoked major blowback, it should be expected that other powerful countries, such as China, might consider adopting it.
Smaller nations, too, have taken note. There are politicians in countries along the EU's eastern edge that would prefer to move out of Moscow's orbit. The message the seizure of Crimea – and, before it, the attack on Georgia – sent is that Russia is able to act in favour of its interests with, if not impunity, then at least negligible consequences.
For countries such as Montenegro, where Russian nationals have been accused of plotting a 2016 coup d'etat, or Macedonia, where the US and Russia openly vie for influence, a lack of dependable international rules is a real threat, and can drastically influence a country's political realities.
Undermining international rules so blatantly carries consequences. It empowers those with the ability to do the same and places those without in danger.
The long rule of Vladimir Putin is sometimes said to have taken Europe back to the Cold War. In fact, it is a throwback to an even earlier time. By holding Crimea for so long, and with so few consequences, Russia has pulled off the most blatant land grab in Europe since the 1940s.