Lawyers for a Ukrainian ex-military officer accused of leading the bombing of Russia's Nord Stream pipeline in September 2022 argued at the start of his trial in Germany on Wednesday that "an aggressor's infrastructure" may have been a lawful target.Serhii Kuznetsov is accused of leading a group of Ukrainian agents including divers and an explosives expert that blew up Russia's largest gas pipeline to Europe in one of the biggest infrastructure sabotage operations of modern times.The case provides the first opportunity for a public hearing of evidence gathered during a years-long investigation, which has been diplomatically and politically awkward for a German government that remains staunchly supportive of Ukraine despite the investigative trail linking Kyiv to the bombing.Moving to have the case dismissed, Kuznetsov's lawyer Nicola Canestrini argued that the pipeline — which provided half of Germany's imports of natural gas before Russia's 2022 invasion of Ukraine — was a "Russian weapon"."Is it unlawful to destroy an aggressor's infrastructure without harming any human beings?" Canestrini asked.Right to remain silent