Operation Backstop

Operation Backstop was a United Nations Protection Force (UNPROFOR) military plan designed to guard a portion of the United Nations Protected Areas (UNPAs) against attack by the Croatian Army (Hrvatska vojska – HV) during the Croatian War of Independence. Operation Backstop was developed by the UNPROFOR staff in charge of the UNPA Western Slavonia (Sector West) in 1992. It was scheduled to be implemented by two mechanised companies of the Canadian battalion deployed in the area.

While no HV attack occurred in the area during the UNPROFOR mandate, elements of the plan were carried out by the 3rd Battalion of the Princess Patricia's Canadian Light Infantry (PPCLI) as the HV clashed with the Army of the Republic of Serb Krajina (ARSK) in Operation Maslenica in January 1993. The 2nd Battalion of the PPCLI practiced implementation of the plan in March 1993 to demonstrate UNPROFOR's resolve. Deputy commander of the UNPROFOR in the Sector West considered the plan impractical due to force security concerns, except in terms of deterrence.

Background
In November, Croatia, Serbia and the Yugoslav People's Army (Jugoslovenska Narodna Armija – JNA) agreed upon the Vance plan, designed to halt combat operations in the Croatian War of Independence and allow negotiation of a political settlement. Besides the ceasefire, the plan entailed protection of civilians in specific areas designated as United Nations Protected Areas (UNPAs) and UN peacekeepers in Croatia. The ceasefire came into effect on 3 January 1992. Shortly after the Vance plan was accepted, the European Community announced its decision to grant a diplomatic recognition to Croatia on 15 January 1992, while the Serb- and JNA-held areas within Croatia were organised as the Republic of Serbian Krajina (RSK).

Despite the Geneva Accord requiring an immediate withdrawal of JNA personnel and equipment from Croatia, the JNA stayed behind for seven to eight months. When its troops eventually pulled out, JNA left their equipment to the RSK. As a consequence of organisational problems and breaches of ceasefire, the UN peacekeepers named the United Nations Protection Force (UNPROFOR), did not start to deploy until 8 March. The UNPROFOR took two months to fully assemble in the UNPAs. The UNPROFOR was tasked with demilitarisation of the UNPAs, ceasefire maintenance, monitoring of local police and creating conditions for return of internally displaced persons and refugees. Those comprised more than 300,000 Croats who were exiled from the RSK-controlled territory, and 20,000 Serbs who fled areas of the western Slavonia captured by the Croatian Army (Hrvatska vojska – HV) in Operations Swath-10, Papuk-91 and Hurricane-91 in late 1991.

A part of the western Slavonia, encompassing an area extending approximately 90 by was designated as the UNPA Western Slavonia or Sector West by the peace plan. Unlike other UNPAs, the RSK controlled only a part of the area—approximately a third of the UNPA located in the south, centred on the town of Okučani. The RSK-held area included a section of the Zagreb–Belgrade motorway. The Sector West was divided into four areas of responsibility (AORs). The western portion of the motorway section and its surroundings were assigned to a Jordanian battalion of the UNPROFOR (JORDBAT), while the area to the east, containing the rest of the motorway within the UNPA and the town of Okučani was AOR of a Nepalese battalion (NEPBAT). To the north of the JORDBAT and NEPBAT AORs, a Canadian battalion (CANBAT 1) AOR was set up. The northernmost portion of the Sector West became the AOR of an Argentine battalion (ARGBAT). Unlike the Canadians, who had at their disposal 83 armoured personnel carriers, the Jordanian and the Nepalese troops were armed with small arms only. The Sector West was commanded by the Argentine Brigadier General Carlos Maria Zabala. The bulk of the staff work was taken over by the Canadians.

Canadian order of battle
Initially, the CANBAT 1 consisted of elements of the 1st Battalion of the Royal 22nd Regiment, the 3rd Battalion of the Royal Canadian Regiment (RCR) and the 8th Canadian Hussars, under command of Lieutenant Colonel Michel Jones. Lead elements of the unit reached Croatia on 8 April, and it took two weeks for all the CANBAT 1 troops to arrive. In September 1992, the CANBAT 1 troops were replaced by the 3rd Battalion of the Princess Patricia's Canadian Light Infantry (PPCLI). The CANBAT 1 was headquartered in Polom Barracks, situated between the towns of Pakrac and Daruvar.

The CANBAT 2 was established and ordered to Serb-controlled part of Bosnia and Herzegovina. It consisted of the 2nd Battalion of the RCR and an additional company drawn from the 1st Battalion of the RCR. The CANBAT 2 arrived to the area in mid-November 1992, and attempted to enter the Bosnian Serb-controlled territory through the Sector West, but Bosnian Serb authorities turned them back, forcing the CANBAT 2 to establish a base in Lipik, in the Sector West instead. The unit remained in the area until February 1993.

Plan
The UNPROFOR operations staff in the Sector West developed several plans for defence of the sector, assigning the top priority to the scenario considered the most feasible. The plan was codenamed Operation Backstop. It envisaged an active defence against the HV, assuming that the main axis of the attack would be aligned with the Zagreb–Belgrade motorway. The CANBAT 1, supported by Zabala, thought the HV would attack the Sector West in order to establish control of the Zagreb–Belgrade motorway and that the UN would not object to such a move.

The CANBAT 1 was expected to deploy a mechanised company each to the JORDBAT and the NEPBAT AORs to position themselves in prepared defensive positions. Once in place, the force would attempt to deter the HV from advancing, demonstrate its resolve to defend the Sector West, engage the HV using antitank weapons and mortars, protect the Jordanian and Nepalese withdrawal and then withdraw under protection of the rest of the CANBAT 1. The two companies required an eight-hours-notice of the HV advance in order to reach their designated positions in time. Presumably the Army of the RSK (ARSK) would retrieve its heavy weapons from the UNPROFOR storage and resist the HV.

Reaction to Operation Maslenica
In January 1993, when the HV launched the Operation Maslenica aimed at capture of Maslenica Bridge, the Canadian troops acted conforming to a part of Operation Backstop plans. They dug in their positions and reinforced the Nepalese troops for 72 hours, expecting a HV attack in the Sector West. Still, no reinforcements were deployed to the JORDBAT AOR. At the same time, the UNPROFOR prepared to blow up the only bridge across the Sava River linking the Sector West and the Bosnian Serb-held territory in Bosnia and Herzegovina in order to prevent the Army of Republika Srpska from advancing into the area.

In response to Operation Maslenica, the RSK president, Goran Hadžić ordered the ARSK to retrieve its tanks from UN storage in the Sector West and attack Nova Gradiška and Novska. When local RSK authorities, led by Veljko Džakula, in the Sector West demanded explanation of the move, Hadžić responded that the Croatian forces were just about to attack Okučani. On 26 January, Zabala met with Džakula in Okučani and reassured him that the UNPROFOR would protect the Sector West in case of a Croatian attack, agreeing to provide the RSK with a written guarantee to that effect. Hadžić accepted the assurance and cancelled the attack. Nonetheless, the orders were reinstated and cancelled three more times over the next two days. The situation calmed down by mid-February and no HV attack against the Sector West materialized then.

Exercise
The 2nd Battalion of the PPCLI replaced the 3rd Battalion in April as the CANBAT 1. Commander of the 2nd Battalion, Lieutenant Colonel Jim Calvin instructed his troops to approach their tasks differently than the 3rd Battalion. Calvin, unlike his predecessor, did not want either the RSK forces or the HV to be aware of the CANBAT 1 operations and ordered the battalion to observe radio silence. According to Canadian journalist Carol Off, Calvin was eager to fight and earn recognition. He instructed his troops to shoot back if necessary. Overall situation in the Sector West deteriorated after Jordanian General Shabshough replaced Zabala in March.

In order to reassure Croatian Serb population of the Sector West, the CANBAT 1 performed an exercise of Operation Backstop and evacuation of the NEPBAT. Afterwards, the deputy commander of the Sector West, Canadian Colonel K. C. Hague recommended the plan to be redesigned to serve primarily as a means of deterrence. Hague's view was that in case Operation Backstop produced an armed clash with the HV, the UNPROFOR would be forced to withdraw through Croatia exposing the peacekeepers to grave danger.

Aftermath
According to Croatian political scientist Vladimir Filipović, it is unclear whether the limited resources earmarked for the operation and unclear motivation of the CANBAT 1 troops would be sufficient to stop several HV brigades. Hague also pointed out that the plan did not provide any indication how would the CANBAT 1 or the other elements of the UNPROFOR retreat through Croatia after such a clash. Hague also questioned feasibility of Operation Backstop because the advance warning requirement was considered impossible to meet. The UNPROFOR had no reliable military intelligence on HV movements outside the UNPAs, or beyond 30 km wide zones around the UNPAs where only the United Nations Military Observers were present. Hague nonetheless considered Operation Backstop a success in terms of deterrence.

Even though Operation Backstop was perfectly within the UNPROFOR mandate, as the peacekeepers were authorised to use force in order to prevent armed incursions into the UNPAs, Croatian authorities resented the operation. Croatia considered the UNPROFOR to be overzealous in defending the UNPAs and protecting the Serbs while failing to ensure fulfilment of other aspects of the Vance plan, such as return of the refugees to their homes.

By September 1993, the entire CANBAT 1 was relocated from the Sector West to the Sector South in the northern Dalmatia and Lika. UNPFROFOR mandate in Croatia expired for the final time on 31 March 1995. The United Nations Security Council adopted Resolution 981 establishing the United Nations Confidence Restoration Operation in Croatia (UNCRO) instead. The entire Sector West was captured by the HV in Operation Flash in early May 1995 without any resistance from the UN peacekeepers. The main axis of the first day's advance by the HV was indeed aligned with the Zagreb–Belgrade motorway, as assumed by the planners of Operation Backstop.