Association against Bulgarian Bandits
Удружење против бугарских бандита Udruženje protiv bugarskih bandita
Members of the Association against Bulgarian Bandits in Vardar Banovina before 1930
Active	1922–1930
Country	Kingdom of Yugoslavia
Type	Paramilitary
Role	Irregular warfare Patrolling
Commanders
Notable commanders	Kosta Pećanac

The Association against Bulgarian Bandits (Serbian: Udruženje protiv bugarskih bandita, Serbian Cyrillic: Удружење против бугарских бандита) was a paramilitary organization based in Štip, then in the Kingdom of Serbs, Croats and Slovenes, that was active during the interwar period.^[1]

During World War I, the Serbian Army and the Chetnik movement were in conflict with the Bulgarian Internal Macedonian Revolutionary Organization (IMRO) and Army, which occupied most of Serbia and Macedonia. Bands of Chetniks instigated the Toplica Uprising, which was quickly crushed by the Bulgarian soldiers and IMRO chetas. The post-war Treaty of Neuilly denied Bulgaria what it felt was its share of Macedonia and Pomoravlje. This was felt by Bulgaria as a heavy blow, since it was now being forced to return to Serbia, Greece and Romania territories it had briefly occupied during the war, and to pay reparations to those countries.

In the newly formed Kingdom of Serbs, Croats and Slovenes, the Chetnik movement ceased functioning as a guerrilla force. However, the IMRO soon began sending armed bands from Bulgaria into the Serbian part of Macedonia to assassinate officials and stir up the spirit of the Bulgarian part of the local population. In 1921, Bulgarians from the Western Outlands created the Internal Western Outland Revolutionary Organisation (IWORO), which operated in the areas of Tsaribrod and Bosilegrad that had been ceded to Yugoslavia.

The Association against Bulgarian Bandits was set up in 1922 by former Chetniks to provide resistance to the IMRO and to IWORO militants in the areas of Vardar Macedonia and the Western Outlands, with Kosta Pećanac as a leading figure.^[2] Between 1923 and 1924, during the apogee of interwar military activity, a total of 53 armed bands operated in the region of Yugoslav (Vardar) Macedonia, according to IMRO statistics.^[3] The aggregate membership of the bands was 3245 rebels, and 119 armed clashes and 73 terrorist acts were documented.^[4] At the same time, IWORO carried out numerous assaults on the Tzaribrod–Belgrade railway, especially its bridges. Violent Serb counter-measures tended merely to cement the support for IMRO.^[5]

The IMRO, having been reestablished in 1920, had its own left wing and split over the ultimate goal of its activity. The right faction sought the incorporation of all Macedonian territory into Bulgaria, while the left faction wished the establishment of a separate Macedonia with the goal of joining a future Balkan Federation. In December 1921, left-leaning deserters of the IMRO formed the official Macedonian Federative Organization. Violence between the two groups aggravated the political crisis, and led to the growing public impression that the Bulgarian government was unstable. Meanwhile, the government started a military campaign against the IMRO in the summer of 1921, helped by the Federative Organization as an ally. The Premier, Aleksandar Stamboliyski, declared the aim of forming a new Balkan Federation of agrarian states.

In March 1923, Stamboliyski signed the Treaty of Niš with the Kingdom of Serbs, Croats and Slovenes and undertook to suppress the operations conducted from Bulgarian territory by the IMRO and the IWORO.^[6] Responding to this, the IMRO, aided by radical officers, carried out a coup d'état. The fall of Stamboliyski's pro-Yugoslav government was seen as a great success for IMRO. Subsequently, some of the federalists who had fled from Bulgaria placed themselves in Serbian service, joining the Association against Bulgarian Bandits and fighting against the IMRO. Serbian Prime Minister Ljubomir Davidović openly declared his opposition to this, but Žika Lazić, who coordinated the work of the guerrillas, claimed not to have found a better mechanism for the mutual annihilation of current and former Bulgarian Komitadjis.^[7]

As a result of these events, the IMRO, aided unofficially by the new government, came to operate as a "state within the state" in Bulgaria, using it as its hub for swift raids against Yugoslavia. In consequence, the Yugoslav-Bulgarian frontier had at the end of the 1920s been turned into the most fortified one in Europe.^[8] The Serbian actions managed to significantly reduce attacks by the IMRO. In the wake of the May 1934 coup, constant fratricidal killings and assassinations carried out by the IMRO abroad led a group of Bulgarian military officers to take control and break the power of the organization, which had come to be regarded as a criminal grouping inside Bulgaria and a band of assassins outside it. Following this, the Association against Bulgarian Bandits was gradually dissolved.