The move has been prompted by the US war on terror. "The narrow approach to the security agenda driven by the US is undermining the hard-won gains made on human rights," said Amnesty International secretary-general Irene Khan.
"It is reinforcing the privilege of the powerful over the poor and marginalised, and ignoring the real sources of insecurity for most of the people in the world.
"A coalition of powerful states fought two wars in Afghanistan and Iraq purportedly to make the world - their world - safer. But real people feel more vulnerable than ever before."
The organisation's governing International Council decided on the move, which will affect all of Amnesty's 80 national branches, in Mexico last week.
Specific campaign policies will be developed on discrimination of all kinds, refugees and migrants, armed conflict, violence against women and girls as well as economic, social and cultural rights. The move will also see Amnesty campaigning on poverty in the developing world and increase its lobbying work to confront abuse by the corporate sector and armed forces.
In the UK Amnesty is likely to step up its campaign for corporations to take more seriously their obligations towards the human rights of workers.
An Amnesty International UK spokesperson said it was a prime mover in the shift in policy that was agreed in Mexico.
"It provided policies for areas in which Amnesty International has been working for a number of years, and will enable us to work in a more focused way, particularly working with other organisations," she said.