The Islam Tea House in the southeastern Turkish town of Adiyaman is boarded up these days. But it remains a microcosm of Turkey's security fears in the lead up to Sunday's critical poll. A nondescript town around 150 kilometres north of the Turkey-Syria border, Adiyaman is the hometown of four suicide bombers who have been responsible for nearly 140 deaths over the past four months. The four men frequented the Islam Tea House, a fertile recruiting ground for jihadists, which has come to be known as the "Teahouse of Death". The teahouse was eventually closed down, officially for operating without a license. But it was already too late. The men conducted three suicide bombings over the past four months -- which the government has attributed to the Islamic State (IS) group (also known as ISIS or ISIL) – including the October 10 attack in the heart of the Turkish capital. All three attacks targeted the pro-Kurdish HDP (Peoples' Democratic Party). These days, in the mainly Kurdish southeastern city of Diyarbakir, armoured cars and riot vehicles surround police stations, bullet holes pockmark buildings and burned-out cars cluster around some neighbourhoods. The symbolic capital of Turkey's estimated 15 million Kurds, Diyarbakir today looks like a city sliding into civil war. The topic du jour at cafés and kebab stores is whether Turkey is witnessing a return to a decades-old conflict between the PKK (Kurdistan Workers' Party) and Turkish security forces, which claimed around 40,000 lives. The war on Turkey's southern border with Syria has seeped into Turkey's ethnic fault lines. The battle against the IS group for Kobane, a Syrian Kurdish town, collapsed the peace process with the PKK and the government today is battling two terrorist groups, making security the top issue in Sunday's general election. Barely five months after the ruling AKP (Justice and Development Party) failed to win an absolute majority in the June 7 vote and then failed to form a coalition, Turkey heads back to the polls on Sunday in one of the biggest tests of President Recep Tayyip Erdogan's political career. The Turkish leader, whose autocratic style has earned him a derisive "Sultan" moniker, will not feature on the ballot papers on Sunday. The November 1 poll is a general – and not a presidential – election. But in Turkey today, politics is a deeply personalised business and Sunday's vote could determine the extent of power Erdogan can wield in Turkey's future. It could, analysts fear, determine not just Turkey's future government, but whether the country itself will be governable. And no issue underscores those concerns more than security, which has relegated the economy, corruption, EU accession and other concerns to the backburner. "It's crucial," said Jana Jabbour, associate researcher at the Paris-based CERI (Centre de Recherches Internationales) and a lecturer at Sciences-Po. "President Erdogan is trying to use the security card as a means to win the elections. His strategy has been to say either vote for me or there will be a collapse of national unity." Turning a blind eye to IS group threat The irony of a figure as divisive as Erdogan positioning himself as a unifying figure is not wasted on his critics, who blame the Turkish president's domestic and foreign policies for the country's current security crisis. "We've seen a monumental failure of security in Turkey. The government couldn't protect civilians," said Emre Demir, editor of Zaman France, on FRANCE 24's Debate show, referring to the spate of recent suicide attacks. In Adiyaman, family and friends of radicalised youths joining IS group ranks repeatedly complain that they alerted authorities who failed to act. Ramazan Gokay, an uncle of two brothers who joined the IS group's Turkish branch, told FRANCE 24 the boys' parents repeatedly warned officials about their sons. "The police told them that they could do nothing, that they had to control their own children, and that they would only intervene if they committed an offence," said Gokay. Many Adiyaman residents accuse Erdogan of supporting the IS group, a charge the AKP government vehemently denies. But Erdogan's critics claim there is a logic to Ankara turning a blind eye to IS group-inspired radicalism. The IS group, they note, opposes Erdogan's arch foe, Syrian President Bashar al-Assad. The jihadist group also prevents Kurdish expansion along Turkey's southern border with Syria. ‘Trapped by the Sevres syndrome' Turkey joined the US-led coalition air strikes against the IS group in late July. But Kurdish activists say Turkish airpower has concentrated on PKK targets, effectively killing a two-year-old PKK ceasefire and snuffing out any hopes for peace. In southeastern towns like Silvan and Cizre today, armed members of the YDG-H, the youth wing of the banned PKK, act as a paramilitary force in some neighbourhoods, creating no-go zones for Turkish security forces. Erdogan's critics say the collapse of the peace process with the PKK was driven by the Turkish politician's attempt to discredit the HDP, the pro-Kurdish party, which made history in the June 7 parliamentary election when it crossed the required 10 percent vote threshold to enter parliament for the first time. The results of Sunday's vote will reveal whether Erdogan's strategy has worked. Polls ahead of the election show AKP increasing its support among a nationalist vote base worried about a prolonged period of political instability. In the June 7 election, the AKP won 40.9% of the vote while the MHP (Nationalist Movement Party) got 16.8%. Analysts say the MHP carved into the AKP's nationalist vote base that Erdogan is now trying to woo by playing the "tough on security" card. The dangerous cocktail of the IS group and PKK threat, far from hurting Erdogan, appears to be turning the public opinion tide in his party's favour. "So far, from reading the papers, Turkish observers do not seem to be directly blaming Erdogan. Only the Kurdish electorate is accusing him of having pushed for a renewal of violence," explained Jabbour. "But even the renewal of violence could be used as an argument by Erdogan that it's either me or we're facing the empowerment of the Kurds and the disintegration of Turkish territory." The discourse, Jabbour notes, has a powerful resonance in the Turkish imagination that dates back to the World War I-era of colonial scheming to disintegrate and divide the Ottoman Empire. In Turkey, the belief that western forces are conspiring to weaken and carve up Turkish territory is called the "Sevres syndrome" after the 1920s Treaty of Sevres partitioning the Ottoman Empire. "The problem with the Turkish nation is that they have been trapped by the Sevres syndrome. They are really scared that the PKK will establish a separate state at the border," explains Jabbour. "So, when Erdogan says it's either me or Turkish disintegration, it speaks to the political subconscious." The end of an era Meanwhile tensions have been rising in the lead-up to the vote, with a government crackdown on media groups critical of the AKP. The opposition HDP has also warned that the deteriorating security situation in southeastern Turkey could at best deter their Kurdish supporters from voting, at worst provide perfect conditions for voting irregularities. Nevertheless, Kerem Onen, an HDP official, told the FRANCE 24 Debate show he was confident his party would fare well in Sunday's poll. "No, I do not have any fears of losing votes because the HDP is calling for peace," said Onen. AKP officials however say they are confident that this time around, the party will get an absolute majority, a forecast most analysts discount. Jabbour, like many experts, predicts the AKP could fall short of a majority, triggering another season of coalition talks. "But no matter what the results are, they will mark the end of an era in the political system," said Jabbour. "They will mark an end of single party rule in Turkey."