Turkey's front pages yesterday.

In a country where military coups were once an accepted part of political life, and military influence over elected ministers taken for granted, the spectacle of venerable generals carted to prison in dawn raids has sent shockwaves through the system. Some 45 retired and active officers detained on Monday, and questioned yesterday, include senior commanders serving in the first years of the ruling AK party government, when a moderate chief of general staff struggled to check secularist dissent against politicians with Islamist roots. Many of those detained have been linked to the so-called Sledgehammer plot, detailed in documents leaked last month to the Taraf newspaper, which claimed they dated from 2003 and contained internal army plans to stage a coup. "Turkey has taken its biggest step yet to ridding itself of a semi-military regime in which coups have never been treated as a crime and it was normal that they should not be punished," Yasemin Congar, Taraf's deputy editor, wrote yesterday. Ilker Basbug, chief of general staff, has made no public comment on the detentions. He previously denied that the Sledgehammer papers contained coup plans, but authorised a military investigation to run alongside the civilian court probe. The general staff said yesterday that all serving generals and admirals had met in Ankara to discuss what it called a "serious situation". But the detentions could trigger a more serious confrontation between prime minister Recep Tayyip Erdogan's AK party and its traditional antagonists in the secularist bastions of the military, judiciary and Kemalist opposition. A row last week between factions in the judiciary has fed rumours that Turkey's chief prosecutor could be preparing a new closure case against the AK party in the constitutional court, a move that would probably trigger early elections. Mr Erdogan has made little comment on the detentions, perhaps aiming to underline that the government has played no part in the investigation. Although Turkish assets have been hit by the developments, analysts such as Ahmet Akarli, at Goldman Sachs, suggest that neither General Basbug nor Mr Erdogan stands to gain from tensions, "as this would risk a more serious political crisis with highly unpredictable consequences for all parties involved". But the AK party has found in the past that its run-ins with the army worked in its favour at the polls. After military intervention failed to prevent Abdullah Gul's appointment to the presidency in 2007, the AK party won re-election with 47 per cent of the national vote, a landslide by the norms of Turkish elections. Now Gen Basbug is likely to come under pressure from his staff to toughen his approach, though he has stressed that the era of military coups is over. Mr Erdogan, meanwhile, is threatening a fresh push for constitutional reforms that the AK party has attempted before . Develet Bahceli, leader of a nationalist opposition party, said he would not support constitutional change before the next elections, meaning that the AK party's only option would be to call a referendum and seek a popular mandate. The latest developments have underlined both the need for constitutional change, and the difficulties of pursuing reforms in a polarised political climate. "What I see is an unravelling . . . We have to reconstruct the regime in Turkey and there is not the minimum degree of consensus as to what the primary rules, principles, institutional changes ought to be," said Soli Ozel, an academic at Bilgi university. Henri Barkey, a visiting scholar at Washington''s Carnegie Endowment, warned the biggest challenge could come when Gen Basbug's term ended this summer, as he was set to be replaced by a hardliner. "Turkey is at an inflexion point," he said. "Either it will face political instability in the near future or it will have to make a serious attempt at changing the constitution. Doing nothing is not an option." Timeline Feb 2010 Former chiefs of navy and air force among more than 40 retired and serving officers detained for questioning in connection with Sledgehammer Jan 2010 Taraf publishes details of "Sledgehammer" documents, claiming generals drew up scenarios for military coup in 2003 2008 AK party narrowly escapes closure by constitutional court for undermining secularism. Trial begins of so-called Ergenekon network, accused of planning violent attacks to destabilise government 2007 Army interference and secularist rallies fail to stop Abdullah Gul's appointment to presidency and AK party's re-election with 47 per cent of vote