fIn his final press conference today, President Obama gave new insight into his surprise decision to commute the sentence of Chelsea Manning.

“Chelsea Manning has served a tough prison sentence,” the president told reporters. “It has been my view that given she went to trial that due process was carried out, that she took responsibility for her crime, that the sentence she received was very disproportionate relative to what other leakers had received, and that she had served such a significant amount of time that it made sense to commute and not pardon her sentence. I feel very comfortable that justice has been served.”

President Obama’s order did not pardon Manning or vacate her conviction, but it did reduce her sentence to just over seven years, the vast majority of which has already been served. Manning is scheduled to be released in four months, on May 17th.

Manning was initially sentenced to 35 years for her role in providing classified information to Wikileaks, and has faced significant disciplinary actions — most recently, seven days in solitary confinement — as a result of conflicts with the prison administration. Wikileaks founder Julian Assange had promised to surrender himself to authorities if Manning was pardoned. Assange has since backed off on the promise, stating that yesterday’s order does not fulfill the terms of the pledge.

Speaking to reporters, President Obama framed the clemency order in light of encouraging whistleblowers to report abuse, an area in which he has drawn significant criticism in the past.

“I think all of us, when we’re working in big institutions, may find ourselves at odds with policies that have been set,” President Obama told reporters, “but when it comes to national security, we’re often dealing with people in the field whose lives may be put at risk.”

“That has to be kept in mind,” he continued.