The documents show that Amir Ardebili gave a stark explanation for why he was trying to buy so many different weapons parts, including technology that would help protect Iran from missile attacks.
"By his own admission, Ardebili was assisting Iran in preparing for war with the United States," prosecutor David Hall wrote in a sentencing memorandum.
Ardebili "directly threatened the security of the United States," the prosecutor wrote. "He was a prolific acquisitions agent procuring or attempting to procure a wide range of components, for his sole customer, the government of Iran."
The papers also said that during a 2007 meeting with an undercover agent, Ardebili said he wanted so much material in case the U.S. goes to war with Iran, so that "the government (of Iran) could defend... Because they think the war is coming."
The case represents the latest example of what past and present U.S. officials say is an intense and ominous effort by Iran to evade export controls and acquire critical military technology amid a long-running standoff with the West over its nuclear program.
Federal authorities are set to discuss at a Delaware news conference the case against Ardebili, following a lengthy investigation by Immigration and Customs Enforcement agents. Court papers say he secretly pleaded guilty May 2008 to a number of charges, including violating the Iranian arms embargo.
Ardebili was arrested in 2007 following a clandestine meeting with an undercover agent in the Caucasus nation of Georgia.
His capture has already been the subject of tense back-and-forth, after the Iranians complained this year of his earlier arrest in the Caucasus nation of Georgia. The Iranians have argued to United Nations officials that Ardebili and a handful of others have been improperly seized through U.S. efforts.