With fighting intensifying in the pro-Russian rebel enclave in eastern Ukraine, security of the MH17 investigators and the crash site is imperative. 

A temporary cease-fire proposed after the destruction of MH17 last week never materialised. Ukrainian military forces have launched an offensive in the city of Donetsk, where heavy shelling is being reported. Two Ukrainian fighter jets were shot down on Wednesday south of the MH17 crash site. There are further reports of investigators on the scene being 'chased away' by separatist rebels.

It is becoming clear that some form of international security force will need to be employed for the investigation to carry on in the long-term.

This force will need to be more substantial than the 40 unarmed military police the Netherlands intends to send and the 50 Australian Federal Police that Prime Minister Tony Abbott says are on standby.

Yesterday morning Foreign Minister Julie Bishop gave a hint of one of the options under consideration by the OSCE and the Australian, Dutch and Ukrainian governments: peacekeepers. Peacekeepers under a UN mandate may be the best option to provide security for the crash site and are likely to be the most politically expedient. 

The UN Security Council mandate secured by Australia and the Netherlands earlier this week leaves open the option of using a peacekeeping force to secure the crash site and the safety of international investigators. The language used in the mandate is clear. The Security Council called for a 'full, thorough and independent international investigation into the incident', demanded that the armed rebel groups in the area 'refrain from any actions that may compromise the integrity of the crash site' and most importantly expressed 'grave concern at reports of insufficient and limited access to the crash site.'

A UN peacekeeping operation could be built off this mandate. Such an operation would need to be authorised by the Security Council and passed by its five permanent members, including Russia. This would be difficult, but Russia passed the resolution authorising the investigation earlier this week on the condition that the resolution did not assign blame. Moscow could see this as an opportunity to show goodwill and further de-escalate the situation, particularly if the peacekeeping forces came from countries outside of NATO.

To a degree, the crisis in Ukraine is driven by what Russia considers the creeping influence of the European Union and NATO along its 'near abroad'. Russian President Vladimir Putin has repeatedly cited the expansion of NATO membership to former Soviet Republics as a threat and would probably never accept a NATO security mission to eastern Ukraine.

A UN peacekeeping operation could include forces from more politically appealing non-NATO countries. While forces from Australia and the Netherlands would be included (they may even establish a bilateral security force to go in immediately), in the coming months personnel from non-NATO countries could be integrated into the operation. Malaysia and Indonesia, which suffered significant causalities in the incident, may wish to participate. Other major peacekeeping countries like India and Brazil could be asked to contribute.

It is critical to establish security around the site to ensure the investigation into the cause of the MH17 disaster can proceed unhindered. Moreover, the speed with which the investigation can commence in earnest will be crucial in determining the fate of MH17 and ensuring that justice can be delivered for the victims and their families. The investigation is also likely to take some time; the investigation at the crash site of Pam Am flight 103 took months. Ensuring the safety of investigators is also a high priority.

A multinational UN peacekeeping operation is the best way the meet all these objectives.

Photo by Flickr user Jeroen Akkermans.