An Islamic State sympathiser has been jailed for life for plotting to carry out a beheading attack around Remembrance Sunday.
Nadir Syed, 23, targeted a poppy seller before his arrest shortly before Armistice Day in November 2014.
He had obtained a large, sharp kitchen knife after listening to a speech by IS spokesman Abu Muhammad al Adnani, which also urged extremists to target France.
Following a trial at Woolwich Crown Court last year, Syed, from Hounslow, west London, was found guilty of planning a terrorist attack.
Syed planned an attack like the one that killed Fusilier Lee Rigby
Sentencing him at the Old Bailey to a minimum of 15 years, Mr Justice Saunders said: "I am satisfied like the killers of Fusilier Rigby, Nadir Syed followed the precept of an eye for an eye and a tooth for a tooth.
"In my judgment if he was released from prison he would go and try to carry out what he failed to achieve in this case - he would set out to kill in furtherance of his beliefs."
He added: "The defendant will remain dangerous until the threat from Islamic terrorists has gone."
Until he is safe to return to the community, he will stay behind bars, the judge said.
Syed's cousin Yousaf Syed, 20, of High Wycombe, Bucks; and Haseeb Hamayoon, 29, from Hayes, west London, were acquitted of planning terrorist acts following a retrial.
The court heard the Syeds had tried to travel to Syria via Turkey in January 2014, but Nadir was stopped from boarding a plane because he was on bail for a public order offence, while Yousaf went no further than Turkey.
Instead, Nadir found inspiration in IS propaganda urging attacks on military and police in the West - which he considered to be justification for an attack on home soil.
He appeared before magistrates for a public order offence on 6 November, and after being handed an Asbo, he walked out of court, watched by undercover police teams.
Officers arrested all three men that day - just three days before the potential bloodshed on Remembrance Sunday.
Mr Justice Saunders described images Syed exchanged with other extremists online as "sickening".
They included "glorifying" photos of severed heads, hostages about to be decapitated and pictures of Fusilier Rigby's killers celebrating.
He said: "There was IS propaganda material... there were celebrations of the events of 9/11, there was abuse of those Muslims who sought to prevent the death of hostages," Mr Justice Saunders added.
Syed, who sat in the dock wearing a grey prayer cap and with a full beard, did not react as the sentence was passed.
Mark Summers QC said in mitigation that the plot was "embryonic" and "may never have come to fruition".
"This is about the least complex and sophisticated knife plot one could conceive of," he added.
Syed was raised in the UK along with his three younger siblings before spending two years in Pakistan from the age of 16 to 18.
He was doing an apprenticeship and looking for employment at the time of his arrest, the court heard.
Mr Justice Saunders said the public owed a debt of gratitude to those working for law enforcement who managed to foil the attack.
"If they had not done their job so well, an innocent member of the public would probably have been butchered on the streets of this country."