The pattern of events is depressingly familiar. An Israeli tourist group is targeted for attack by an extremist cell. The bomber blows himself up using at least three kilogrammes of TNT and succeeds in killing five Israelis and their bus-driver. Israeli leaders are quick to blame Hizbollah and the movement's Iranian sponsors. But the thing that made this attack different was that it was perpetrated not in the middle east but in Bulgaria, a member-state of the European Union.

This particular incident took place on 18 July 2012 in Burgas, a resort on the Black Sea coast of Bulgaria, which claimed seven lives and injured thirty-three. It has profoundly shocked Bulgarians, for it is the first terrorist atrocity of this kind on their soil since 1945. A country which is both friendly and open to visitors and peaceable toward its neighbours will now have to reckon with a significantly more challenging security equation.

Although the attack seemed to come out of the blue, there were at least some indications that Bulgaria could be a target for such a strike. Indeed, commentators have been warning for many years of the vulnerability of the Black Sea coast to such attacks from either violent jihadists or state-sponsored terror units. There are two main reasons for this.

The international dimension

First, Israeli citizens have long pursued a love-affair with Bulgaria's coastal resorts. Burgas is a two-hour flight from Tel Aviv, thus easily within reach of Israeli travellers. The Black Sea coast is blessed with wonderful stretches of sandy beach, good food, a reliably warm climate, and an increasingly sophisticated and modern range of shopping options. The tourist infrastructure has rapidly developed over the last decade, and though prices have increased considerably the region (and Bulgaria generally) still represent an economical destination.

For Israelis, these positive features of the Bulgarian tourist environment are amplified by an important historical connection. The close links between Bulgaria and Israel date the second world war, during which almost all Bulgaria's Jewish population was saved from annihilation by the Nazi death-machine. The popular folk-memory of the period includes the often-stated view that Bulgaria’s King Boris III "saved the Jews".

This is not quite true. Boris was a rather weak leader and in the unhappy position of being a supplicant to the Nazis, even if he managed to avoid a direct Nazi invasion. When confronted with multiple and ever more insistent "requests" to surrender Bulgaria’s Jewish population for "transport" to Poland, Boris steadfastly refused to comply. The king’s reasons may have had as much to do with Bulgaria’s domestic politics; and scholarly work demonstrates that it was at local level and through the sustained efforts of parliamentarians that the "salvation of the Bulgarian Jews" took place (local officials simply refused to surrender "their" Jews, who were considered nothing other than Bulgarians). Moreover, many ordinary people saved the lives of their neighbours.

Boris was posthumously awarded the Jewish National Fund's medal of the legion of honour, the first non-Jewish person to receive one of the Jewish community's highest honours. The important legacy of this episode is that, in the Israeli popular mind, Bulgaria is viewed as the friendliest of European states; by the same token, the propensity of large numbers of Israelis to holiday in Bulgaria has made the Balkan country a target for a variety of terrorist groups. As Dimitar Bechev points out, Burgas alone received 30,000 Israeli visitors in July (see "Bulgaria, terror and aftershock", 20 July 2012).

Second, Bulgaria has been a member of Nato since 2004, and has forged a close foreign-policy relationship with the United States. In the transition from communist rule after 1989, Bulgarian elites placed a high priority on entering Nato, and in particular on achieving the security guarantee implicit in Article 5 of Nato's charter. Bulgarian troops served in Iraq after the United States-led invasion in 2003 and have also been present in Afghanistan since 2001.

Bulgaria signed a defence-cooperation agreement with the United States in 2006. This provided for the presence of up to 2,500 US troops in the country and the use of air-bases at Bezmer, Graf Ignatievo and Novo Selo. The Bezmer air-base in particular is expected to become one of the major US strategic airfields overseas. Crucially, the agreement also allows the US to use the bases "for missions in a third country without a specific authorization from Bulgarian authorities". These bases, known as "forward operating sites", provide the American military with an efficient means of projecting power in the Black Sea region and the middle east. This has become even more significant as Turkey has asserted a more muscular foreign policy, independent of its Nato commitments and traditional close ties to both the US and Israel (in the case of the latter, relations were severely damaged by the Mavi Marmara incident in 2010).

The then Bulgarian president, Georgi Parvanov, called the 2006 agreement "a strategic investment in the security of our country". What Parvanov did not reveal to the Bulgarian public was the degree of risk attached to such a security partnership in a context where Washington's "war on terror" had already gone global.

There are currently 600 Bulgarian troops stationed in Kandahar as part of the International Security Assistance Force (Isaf)/Nato force in Afghanistan. Bulgaria increased its contribution to Isaf in 2010 after a letter from President Barack Obama to prime minister Boiko Borissov. In it Obama praised Bulgaria’s stance on the proposed Nato defence-shield and its support for containing Iran’s nuclear ambitions. In the latter context, Bulgaria’s foreign minister since January 2010, Nikolay Mladenov, has repeatedly denied that Bezmer would be used by the Americans as the key base from which an attack on Iran would be launched. Mladenov has also pursued a vigorous middle-east policy which involves both closer ties to Israel and reaching out to "Arab spring" leaders.

Thus, Bulgaria's security calculus has meant balancing the perceived benefits of being inside the Nato club with the risk attached to being identified as a close ally of the US and Israel. It now seems apparent that its affiliation with the latter marked Bulgaria out as a target by enemies of those states.

Bulgarian leaders have been quick to stress that terrorism constitutes a problem for all European states. They must also acknowledge that their own foreign-policy choices may - tragically - have contributed to the Burgas attack.

The political fallout

Bulgaria now has to reckon with the great damage the attack may inflict on its economy. Suicide-bombings by their nature are intended to inculcate apprehension and fear in the areas they take place in. They are not good for business. Bulgaria’s tourism industry, heavily concentrated around the Black Sea coast and contributing over 10% to GDP, has continued to grow even amid the deep and sustained recession across Europe. In the first eight months of 2011, for example, Bulgaria welcomed almost 6.4 million visitors, an increase of 4% on 2010. The World Travel and Tourism Council (WTTC) estimates than by 2017 Bulgaria will be attracting almost 16 million visitors per year, which would represent a doubling of numbers from 2009. It is anyone’s guess how much the Burgas bombing will affect these estimates.

It is worth remembering that, for all its problems - mainly corruption, linked to a voracious post-communist elite’s rent-seeking activity - Bulgaria has made tremendous advances over the past decade. The economy has modernised and begun to deliver a better standard of living for most Bulgarians. The stability of the European Union "anchor" has helped sustain foreign direct investment (FDI), and EU structural funds have helped improve the country’s physical infrastructure. The challenge for Bulgarian policy-makers will be to ensure that Bulgaria’s continued development within the European Union can be balanced with an equally open attitude to its neighbours in the Black Sea and middle east regions.

In the short term the attack also poses challenges for inter-ethnic relations within Bulgaria. For some time there has been speculation about the activities of Salafist Saudis and other foreign militants, who have been trying to radicalise some parts of the Bulgarian Muslim communities, which number about 12% of the population. Those communities are extremely diverse and do not constitute anything like a monolithic group; but there is fear that militant activity is growing within a very small section of the Muslim population. That may or may not be so, and it is so far unclear whether information about the Burgas suicide-bomber will shed any light on this topic. But there is a sense of disquiet, especially in the east and south-east of the country, about the potential for growing militancy.

The Burgas attack has resurrected a familiar set of issues regarding Israel’s relations with its neighbours, and prompted enormous soul searching in Bulgaria. At the very least, it represents the "end of Bulgarian innocence" in the international arena.