As many as 20 US citizens were left out of Thursday’s complex, multi-country prisoner swap with western American allies and Russia, leading those excluded from the deal and their families to express deep disappointment.Among those left behind are Marc Fogel, a US high school teacher from Pennsylvania convicted of smuggling 17 grams of marijuana into Russia and sentenced to 14 years in prison in 2022.Fogel’s name had been included in prisoner swap discussions but his family did not know if he was included by US state department officials. A call from Fogel himself informed them he was not a part of the deal.Being excluded, he told his family, was “soul crushing”, according to the Wall Street Journal.Pennsylvania US senator Bob Casey said that while the prisoner swap was good news for Americans Evan Gershkovich and Paul Whelan, “Marc Fogel is still sitting in a Russian prison”.Casey asked the Joe Biden White House to also prioritize Fogel’s release. “While Marc’s name may not be in the news every day, he is no less deserving of a reunion with his family,” the senator said. “This is a difficult day for Marc and his family.”The choices of who to prioritize in prisoner swap deals is uniquely sensitive, at times depending on a US-determined designation of “wrongfully detained”, which Fogel is not. At other times, a sometimes brutal – but often unstated – calculus about political value to the US becomes a factor.After Thursday’s releases, Vladimir Putin, the Russian president, strode along the red carpet between two rows of rifle-toting honor guards to warmly greet intelligence operatives freed by the deal.“The Motherland hasn’t forgotten about you for a minute,” Putin said, embracing each of them after they walked down the steps of the jetliner that ferried them home, according to the Associated Press.In Washington, Biden and the vice-president Kamala Harris greeted the three freed US prisoners. To that point, the family of Paul Whelan has expressed disappointment that he had remained a Russian prisoner while Brittney Griner, the champion US basketball player, had returned home two years earlier in exchange for the Russian arms dealer Viktor Bout.A US state department spokesperson said that American diplomats were “not going to stop working” to free citizens “that continue to be wrongfully detained or held hostage around the world”.Those still held in Russia are believed to also include Andre Khachatoorian, arrested during a Moscow layover with a licensed, secured firearm in his checked luggage. Khachatoorian’s fiancée said she was “shocked” he was not freed.Ksenia Karelina – a dual US-Russian citizen who worked at a beauty spa in Los Angeles’ Beverly Hills – was arrested and charged with treason while visiting her family in February. Karelina had allegedly made a small financial donation to a humanitarian organization that Russian authorities say is connected to Ukraine’s military.Her boyfriend, Chris Van Heerden, told the Journal that he didn’t know if the 16-prisoner trade meant more exchanges would follow or “that her trial came too late and she was left behind”.Another US citizen, David Barnes, travelled to Moscow while in a custody battle with his Russian ex-wife. He was arrested in 2021 and sentenced to 21 years on allegations that he molested the couple’s children while the family lived in Texas.“I don’t really know what to tell him,” his sister Carol Barnes said to the Journal. “How do I explain that his government just left him behind?” More