It has become one of the most vicious, important and divisive battlegrounds in the 2012 US presidential election.

Since it was legalised in 1973, the issue of abortion has polarised the US, but now the battle has been taken to a new level.

Last year, an unprecedented number of laws have been passed across the US, all aimed at restricting abortion or reproductive rights.

But the fight goes far beyond the medical procedure, with Republican politicians even attacking the Obama administration for making contraception more readily available.

The US has seen more anti-abortion violence than any other country in the world. Since 1993, at least eight abortion providers, including four doctors have been killed. And there have been over 200 arsons and bombings against reproductive healthcare clinics since 1977.

Why is a medical procedure being reframed as a deeply divisive moral issue in the US?

Fault Lines travels to California to meet the next generation of frontline troops fighting to ban abortion, and to Ohio and Tennessee to investigate what lies behind the so-called war on women.