Colonel Denise Lind makes order to determine the level of damage to US from leak of state secrets to WikiLeaks

A military judge has ordered the state department to release into her hands official documents that assessed from the viewpoint of the US government how damaging the leak of state secrets to WikiLeaks had been to American national interests.

The order of the judge, Colonel Denise Lind, came at a hearing in Fort Meade, Maryland, in the court-martial of Bradley Manning. The US soldier has been charged with 22 counts on suspicion of being the source behind the WikiLeaks publications.

For months Manning's defence lawyer, David Coombs, has been pressing the soldier's military prosecutors to hand over in the discovery stage of the trial the official damage assessments. The assessments, carried out by several federal agencies including intelligence bodies, could have a crucial bearing on any sentence handed out to Manning should he be found guilty.

There have been suggestions that the assessments show that in the official opinion of the US government, WikiLeaks did very little to harm US national interests around the world. That could prove invaluable for the defence in mitigation.

Technically, Manning faces a possible death sentence under the charges, one of which accuses him of "aiding the enemy" by acting as the alleged leaker. However, army prosecutors have indicated they will not invoke the death penalty and instead aim for a prison term that could involve life imprisonment.

The judge's demand to see the assessments does not mean that they will be made public. Lind will decide having read them whether or not they should be made available to the defence, and even then they may be classified.

The army prosecutors have consistently resisted any attempt to release the assessments, citing national security. Following the judge's ruling, the state department repeated its insistence that the WikiLeaks trove – including a video of a US helicopter attack on civilians in Iraq and hundreds of thousands of US embassy cables published jointly by the Guardian and other international papers – had been detrimental.

"Our view of the entire WikiLeaks incident has not changed at all in terms of the negative effects. There was enormous turbulence in many of our bilateral relationships when this happened and there have been impacts on individuals," the state department spokeswoman Victoria Nuland said.

Lind said that she would rule on Manning's defence motion to have all the charges against him dismissed on Wednesday. The defence has filed a motion with the military court arguing that the process of the court-martial has been so woefully conducted by the prosecution that none of the charges should be brought to trial.

In his filings, Coombs is scathing about the way the military authorities have gone about the pre-trial preparations. He talks about what he calls the "government's ritual incantations" and says that it has taken two years since the case began for the defence to be handed just 12 pages of discovery materials.

Those materials, he writes, "are dated as of November 2010. Why is the defence receiving these in April 2012, a year and five months after they were prepared?"

As a further demonstration of his low opinion of the military prosecutors, Coombs publishes on his blog all the defence motions that he will be arguing in court this week, stating that in his view "the vast majority of the parties' filings should be made public". This goes against the military prosecutors' request that no motions should be filed for security reasons – Coombs has redacted his filings himself to remove references in the documents that the army has said should not be released.

At the heart of the disagreement over procedures is Coombs's longstanding request for key documents under discovery from the prosecution which he says are crucial to Manning receiving a fair trial.

In particular, the lawyer has tried to obtain access to damage assessments by US intelligence experts. These gave an expert opinion on whether or not the confidential documents that were handed to WikiLeaks, allegedly by Manning, did any harm to US national interests.

It is Coombs's apparent suspicion that the assessments found that the leak was not of great significance in terms of its impact on American interests – a fact that would certainly be relevant in legal argument over an appropriate sentence for the soldier should he be found guilty.

Coombs also wants to see transcripts of grand jury proceedings held in Virginia where it is believed the department of justice has been considering bringing a criminal case against Julian Assange, the WikiLeaks founder. One theory widely held among Manning's supporters is that he has been singled out for harsh treatment in order to force him to testify against Assange who is seen by the US government as their main target.