Vladimir Putin has been quiet about the extent of his forces in Syria, but he’s been even more circumspect about the involvement of his soldiers in eastern Ukraine, where there both mercenaries and national armed forces are kinetically meddling in the affairs of a sovereign state not named Russia.

Fierce fighting between Kremlin-backed militias and Ukrainian forces has intensified and is now the worst it has been since last February. Soviet-era GRAD rockets started raining on the streets and houses of Novoluhanskote in eastern Ukraine right before the holiday season. Once again with every day that passes the war that has killed more than 10,000 people is sending victims to the hospitals and cemeteries on both sides of the front line.

But while public treatment for Ukraine’s soldiers is marked by respect and honor, Russia has kept deaths—and even the names of those soldiers recruited to fight in Ukraine—a secret, while those sent to Syria have been almost as anonymous.

The actual number of Russian casualties is literally a state secret, but there are indicators.

How many Russian contract fighters and recruits have been wounded or killed during the conflict in Ukraine?

Since 2010 the Russian Defense Ministry has not published any data on army losses but some information is still available on the public record. Earlier this year the newspaper Vedomosti reported that a Russian insurance company, Sogas, had won a tender for working with military forces in 2018 and 2019. In its description of the tender the Russian Ministry of Defense published a separate graph for casualties, marked as 6a, which meant death. It said: 596 Russian soldiers died in 2013, 790 soldiers died in 2014 and 626 in 2015.

The actual number is literally thousands of Russians killed in Ukraine at Putin’s command. Back in September 2015, according to this Forbes piece, the best estimate was in the “hundreds, and likely thousands”, and that was over two years ago, but Bloomberg has more recent casualty information, although not split out by country and does not include mercenary casualties. We don’t know more from the Putin Kremlin because it is a state secret by law, and divulging such information by Putin subjects in PutinLand is punishable by jail time. The families of fallen soldiers get insurance money, presumably with strings attached.

For those skeptics who continue to deny Putin’s active role in eastern Ukraine, there are ten things you should know.

1. Thousands of Russian soldiers have died in Ukraine.
2. Some former and current leaders of the DPR/LPR are Russian citizens.
3. The Kremlin calls the shots in the republics.
4. Donbas separatists receive significant military support from Russia.
5. The economies of the “republics” depend on Russian money.
6. Numerous media reports document Russia’s involvement in the war.
7. Independent think tanks have presented proof of Russia’s involvement.
8. More evidence of cross-border shelling from Russia in the summer of 2014 is emerging.
9. The downing of Malaysia Airlines Flight 17 also proves that Russia has been active in the Donbas since 2014.
10. Russia allegedly uses force to kill DPR/LPR militants who have become an inconvenience.

And we’re not even talking about Putin’s presence in the Crimean region of Ukraine, which has since been absorbed into Putin’s nation-state.