How so? Literally, the US released them on the grounds that they did not fit the definition of "enemy combatants", more specifically the part about them acting against the US.
This US administration has been releasing all sorts of dangerous terrorists.
The Uighurs were captured in Afghanistan and held for years. The US studied their status in depth and released a lot of the result...and we have no idea what types of back channel information has been passed to the PRC.
For this administration, using technicalities for releasing these sorts of people is not new. But the fact remains, it became apparent that tmany of hese people were not directly affiliated with the Taliban or Al Quida. The law states that in order to be "enemey combatants," they had to be. The US is restricted by its own legal proceedings, passed by Congress, so a change int the status of those we new were not involved was going to happen sooner or later.
However, there were a number of Uighurs detainees where we did not know, and even highly suspected that they were involved. They could have found reasons to keep those people.
My guess is that the PRC knew and knows a lot of info about these characters, and that they are keeping an eye on them. The PRC agreed to come tpo RIMPAC and participate in the largest US sponsored military exercises available. The Chinese recently particpated in Australia in more military exercises in the out back.
I do not believe China would proceed with such exercises, which bring the two nations closer together, if it thought for a moment...for an instant...that the US had, in essence, turned loose these people purposefully to go off and fight against China and export terrorism there.
That part of the accusation, IMHO, just does not pass the smell test.
Having said that, tIMHO, he Obama adminsitration has made a lot of real dunder-head moves when it comes to the fight against radical Silamic Terrorism. Any of these people who were caught planning to undertake terrorism attacks against any peaceful nation, particularly one of the US's largest trading partners, should never have been released at all.
Even with the US law, pretexts and loopholes could have been found to keep them legally if they had wanted to. I have to believe that it was a pure political move, meant to placate this admin's base...but I also have to believe that a LOT of info was passed to the PRC regarding these people.
Breaking down the nubers held and released:
2006 - 5 relatively minor Uighur detainees released who had minimal or no traiing and were not considered dangerous.
2009 - 11 serious Uighurs captives released, 7 listed as "Enemy combatants," but whose status was changed.
2010 - 2 Uighurs captives released, one of which alleged to have spent time at a Taliban camp, but denied it.
2012 - 2 Uighur detainees released. One alleged Al Quida member, one alleged guarded Al Quida safe house.
2013 - 3 Uighur detainees released, all of whom originally listed as "Enemy combatants," but whose status changed.
IMHO, and from what I have read, outside of maybe the 2006 releases, who appeared to have been caught up in the war without being active recruits or members of combatant groups, many of the others should not have been released at all.