THIS weekend, Chileans celebrate their country's independence from Spain in 1810. They will also celebrate another sort of freedom—from the last vestiges of the 1973-1990 dictatorship of General Augusto Pinochet. On September 17th, President Ricardo Lagos is due to sign a reform of Chile's constitution, deleting what he calls the “authoritarian enclaves” left in place by the dictatorship in a bid to perpetuate the armed forces' political power after civilian government was restored.

The reform, approved by Congress last month, allows the president to fire the armed forces' commanders. The National Security Council, a military-dominated body, has been stripped of all but advisory powers and can now be convened only by the president. Nine appointed senators, who include four former military commanders, will not be replaced when their eight-year term ends in March.

The enclaves from the past had long irritated the centre-left coalition called the Concertación which has governed Chile since 1990. The armed forces and their supporters on the right lost much of their previous appetite for defending these powers after General Pinochet was arrested in London on human-rights charges in 1998.

That made reform possible. But the opposition held out against the government's desire to reform an electoral system under which both houses of Congress are elected in two-member constituencies, with the coalition that comes second needing only a third of the vote to secure one of the two seats. In most constituencies, the Concertación and the opposition each wins one seat. The effect, points out Patricio Navia, a political scientist, is that the parties choose who gets into Congress and have an “insurance policy against defeat”. Under the reform, the electoral system is no longer written into the constitution, making it easier to change in future.

Michelle Bachelet, the Concertación's candidate in a presidential election in December, wants to do that. But the presidential term is being cut from six years to four. The aim is that elections for president and Congress will coincide. It means that Ms Bachelet, if she wins, will have less time to enact difficult reforms. But the opposition's divisions—it has two rival presidential candidates—may weaken its showing in the Congressional election, allowing the Concertación to pick up both seats in some constituencies. In any event, from now on the politicians, not the generals, will take the big decisions, even if some Chileans feel their vote does not count for much.