When a democracy is degenerating into tyranny, it is the free press that is the first to be attacked. Vladimir Lenin went from supporting a free press in opposition to smothering it once in power.

The Nazis branded the free press of the Weimar Republic the “Luegenpresse” (lying press) to undermine it, and then destroyed it under Adolf Hitler. When Vladimir Putin came to power in Russia in 2000, one of his first decrees was on the Information Security Doctrine of Russia, which made information an issue of national security. Putin’s first attack on the free media came just a year later in 2001, when NTV, one of Russia’s biggest independent channels, which had been critical of him and the Second Chechen War, was taken over by the state-controlled Gazprom Media. NTV’s criticism of Putin was quickly stifled.

So it is disturbing when free journalists are attacked, editorially and especially physically — it is a sign that democracy itself is threatened.

Attacks on journalists are becoming more frequent in Ukraine. The latest incident happened on Nov. 7, when journalists working for Radio Free Europe/Radio Liberty’s “Schemes” investigative program were assaulted by bodyguards of Ukrainian multimillionaire and Putin friend Viktor Medvedchuk, a cancer on Ukrainian society for many years, as they tried to film him arriving in Kyiv in his private plane, which had made a direct flight from Moscow.

The same team was assaulted and illegally detained by Security Service of Ukraine, or SBU, officers in September 2015 when filming the luxury cars of SBU officers at their headquarters — cars that SBU officers could not afford on their official salaries. Two years later, no action has been taken against the officers; the legal case is continually stalled.

Other journalists, from the Slidstvo.info investigative program, were shot at in April when filming at the estate near Kyiv where a vast mansion is being built by billionaire oligarch Rinat Akhmetov. The journalists reported five shots fired at them from within the estate. Police opened an investigation. There has been no progress.

In July 2016, Ukrainian-Belarusian journalist Pavel Sheremet was murdered in a car bomb attack in Kyiv. An independent investigation found that a man connected to the SBU was loitering near Sheremet’s car before the bomb was planted, yet there has been no progress in the official investigation into the murder.

There is a long history of attacks with impunity against journalists, going back even before the Sept. 16, 2000 kidnapping and beheading of journalist Georgiy Gongadze, the co-founder of Ukrainska Pravda. Ex-President Leonid Kuchma and his top cohorts remain the top suspects in ordering the crime despite their denials. Yet Yuriy Lutsenko, the prosecutor general, is abdicating his public responsibility to bring the case to an end.

These cases are all warning signs. They must not be tolerated. All those who threaten, assault or kill journalists must be punished for their crimes. Nothing less than democracy is at stake.