Former US military intelligence analyst Chelsea Manning has questioned Barack Obama’s legacy after the former Democratic president commuted her sentence last week, and is calling for “an unapologetic progressive leader” to fight for minorities’ rights.

While not mentioning US President Donald Trump by name, Manning wrote in Britain’s the Guardian that “after eight years of attempted compromise and relentless disrespect in return, we are moving into darker times” and urged Democrats not to compromise.

Trump responded in a tweet, calling her a traitor and criticising the decision to release her.

“Ungrateful TRAITOR Chelsea Manning, who should never have been released from prison, is now calling President Obama a weak leader. Terrible!” Trump wrote.

Manning had been sentenced to 35 years in prison after committing the biggest breach of classified information in American history in 2010 by handing over US government secrets to anti-secrecy group Wikileaks.

In one of his final actions before leaving office last week, Obama commuted Manning’s sentence to about seven years, allowing it to end on May 17.

Republicans, including Trump’s spokesman, criticised the commutation as a dangerous precedent for leakers.

Obama has defended the move, saying Manning had served a tough sentence and that justice had been served.

He also said it was unrelated to WikiLeaks founder Julian Assange’s pledge to accept extradition to the United States, where there is an open criminal investigation into the group’s activities, if Manning was freed.

Wikileaks, in its own tweet on Thursday, rejected Trump’s assertion as “wrong”, noting that Manning was found not guilty of the most serious charge, aiding the enemy.

Manning, formerly known as US Army Private First Class Bradley Manning, was born male but revealed after being convicted of espionage that she identifies as a woman. She has struggled to cope as a transgender woman in a men’s military prison and last year attempted twice to die by suicide.

In her Guardian piece, she did not directly acknowledge Obama’s commutation. Instead, Manning said the former president compromised too much and left a “vulnerable legacy” with “very few permanent accomplishments”.

She raised concerns about worsening healthcare, increased criminalisation of racial minorities and “queer and trans people”, and she urged political progressives to prepare to dig in and push for “change at every level.”

“The one simple lesson to draw from President Obama’s legacy: Do not start off with a compromise. They won’t meet you in the middle. Instead, what we need is an unapologetic progressive leader.”

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