At a press conference in London, the lifelong anti-war campaigner will call for a change in how the UK operates in the world and handles domestic security.
He is expected to reiterate his longstanding view that engaging in wars like those in Iraq and Libya increase the threat of terrorist acts occurring at home.
He is also expected to connect the Manchester suicide bomber, who killed 22 people on Monday, with the wars the UK has taken part in or backed since 2001.
Leaked excerpts suggest he will argue: “Many experts… have pointed to the connections between wars our government has supported or fought in other countries and terrorism here at home.”
He will stress, however, that the link between war and terrorism does not justify attacks on innocents.
“That assessment in no way reduces the guilt of those who attack our children. Those terrorists will forever be reviled and held to account for their actions,” he will say.
“But an informed understanding of the causes of terrorism is an essential part of an effective response that will protect the security of our people that fights rather than fuels terrorism,” Corbyn will add.
Labour’s current leader has opposed joining military interventions at the initiative of his own party – then led by Tony Blair – in Iraq and Afghanistan, and those that were launched under the Conservatives in Libya and Syria.
“We must be brave enough to admit the ‘war on terror’ is simply not working,” he will say.
“We need a smarter way to reduce the threat from countries that nurture terrorists and generate terrorism.”
He is also expected to criticize cuts in police, which government critics claim have led to the army being deployed to make up for a shortfall in armed officers.