When Russia releases an American citizen from prison, the US normally hands someone over in return.

Think Wall Street Journal reporter Evan Gershkovich and the mass prisoner swap in 2024. Or how basketball star Britney Griner was traded for convicted Russian arms dealer Viktor Bout in 2022.

But this time it was different. One-way traffic. After more than four years behind bars, former US marine Robert Gilman was freed by Russia, and no one went the other way.

That's very unusual. Moscow seldom gives anything up for free. So why has Vladimir Putin agreed to it?

Gilman's release follows reports last week that he was close to death. According to an unnamed US official quoted by Reuters, the Russian president granted the former marine's release as a "goodwill gesture".

Has Putin suddenly gone soft? Is hostage diplomacy now a thing of the past? I very much doubt it.

Instead, this feels like a not-so-subtle attempt by the Kremlin to curry favour with the White House in the hope it'll bring diplomatic dividends. (No prizes for guessing where Moscow will want to cash those in.)

Gilman's release comes at a time when Russia's war against Ukraine is causing problems back home.

Ukraine war: Latest updates

Drone attacks deep inside Russia are becoming more frequent. Repeated strikes on oil refineries are hurting the economy and drawing unwelcome attention to Moscow's military shortcomings.

But after four and a half years, there's still no end in sight to the conflict. US-brokered peace talks are a distant memory, having stalled after Donald Trump launched a war of his own against Iran.

To make matters worse for Moscow, the American president appears to have grown closer to Putin's adversary, Volodymyr Zelenskyy, in that time. The pair met in Washington DC at the end of July, amid speculation the White House is warming to Kyiv's cause.

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It's a long way from the atmosphere this time last year, when Trump rolled out the red carpet for Putin in Alaska and appeared poised to cut a peace deal that caved to the Kremlin's demands.

Gilman's release is an attempt by Moscow to rekindle the relationship and get things back on Russia's track. It's designed to present Putin as a reasonable partner whom Trump can do business with.

For now it's a gift, but Russia will undoubtedly be hoping for something in return.