A jury has retired to consider its verdict in the case of Parsons Green Tube bomber Ahmed Hassan.
The 18-year-old Iraqi asylum seeker denies intending to cause harm, telling jurors he made the device as a cry for attention, having developed a fugitive fantasy fuelled by action films.
He said he was "certain" it would not explode, instead "just burn", after testing a sample on the kitchen table - and maintained that the idea of killing someone had never crossed his mind.
But the prosecution has claimed the student was moved by "anger and hatred" when he planted the 400g of explosives on a packed District Line carriage on September 15 last year.
His trial at the Old Bailey heard he told a college mentor that it was his "duty to hate Britain", and from others that he blamed this country and America for the death of his father in Iraq.
Commuters fled as a fireball ripped through the carriage, leaving more than 50 people injured either by the blast or the stampede that followed.
Hassan, who had been living with foster parents in Sunbury-on-Thames in Surrey, denies attempted murder and using the chemical compound TATP to cause an explosion that was likely to endanger life.
In his summing up, Mr Justice Haddon-Cave told jurors a central issue in relation to the bomb was whether a device containing 400g of high explosives and 2.2kg of shrapnel was "a hoax" or not.
He went on: "The prosecution rely heavily on motive in this case and point to evidence that Mr Hassan was angry. He blamed the coalition for his father's death. He had been killed by a bomb in Iraq.
He was angry at the continued bombing of his country by the UK. It was suggested he had a deep down hate of this country."
The judge told jurors that Hassan denied the accusation and said he never had contact with Islamic State.
Sending the jury out just after 12.30pm on Thursday, the judge said: "Be logical, objective, dispassionate. What's required is 12 cool heads."