Plans to rotate a potent 2,500-strong US Marine Air-Ground Task Force through Darwin for six months at a time may fall foul of Australia’s tough biosecurity regulations.

A new report by the US Government Accountability Office ^[1] reveals that it takes two months out of their six-month deployment in the Top End for the Marines to dismantle, thoroughly clean and reassemble vehicles and other equipment they’ll bring to Australia to be sure they’re not carrying weeds, pests or diseases. That’ll likely affect the Marines’ capabilities and increase their costs, the GAO says.

The GAO also says the US Defense Department hasn’t worked out where the Marines should be based during the Northern Australian rainy season when, it notes, flooding’s a significant issue. ‘DOD officials are considering multiple options for the Marines’ location during the rainy season, but no decisions have been made and the options being considered will take years to implement,’ the GAO report says.

In November 2011, the US and Australian governments announced that Marines would come to train in Northern Australia as a key part of the US rebalance to the Asia-Pacific region and, over time, the numbers would build up to a full task force.

Of the 2,500 marines, 1,300 would come from Okinawa, where the US military presence is being reduced. They’d train in Australia during the dry season, from April through to September or October. So far there have been five six-month rotations which began in 2012 with an infantry company of 200 marines. In 2016 the marines sent a 1,250-strong infantry battalion. It’s not yet clear where the balance of the 2,500 marines will come from.

At this stage, the marines from Okinawa are to be gradually relocated to Guam, Northern Mariana Islands, Hawaii and elsewhere in Japan, along with the rotational presence in Australia. The Pentagon officials told the GAO they prioritised planning for Guam over Hawaii or Australia, as the DOD was using money from the Japanese government for the relocation to Guam.

The 2017 Darwin deployment began last week, and this time the Marine battalion brought its versatile Osprey troop carriers and a fleet of helicopters. The task force is designed to allow the rapid deployment of a self-contained Marine force by air, land, or sea on a wide range of missions. It provides its own air and ground support and logistics backup. The size of the force can be tailored for specific operations.

According to the GAO, the US Department of Defense hasn’t resolved what to do about the unavailability of the marines’ equipment while Australia’s biosecurity requirements are met. ‘According to officials at Pacific Command, the biosecurity requirements could result in some Marine Corps equipment being nonoperational for approximately 2 months out of the 6-month rotation,’ the report says. ‘Marine Corps officials stated that, during the approximately 2 months it generally takes to break down, clean, and reassemble the Marine Corps equipment, the equipment is not functional and this hinders capability and training. Officials with the Office of the Under Secretary of Defense for Policy stated that the biosecurity requirements are a risk to the Marine Corps units’ capability.’

To get around the problems triggered by Australia’s biosecurity concerns, an option would be for the Marines to buy a full additional set of heavy equipment that they’d station in Australia, the US officials said. Marine Corps officials told the GAO that was one option being considered. But senior officials from US Pacific Command and the Marine Expeditionary Force said that’s an expensive option and also means that storage facilities had to be found. They told the GAO they’d identified a set of additional equipment that could be left in Australia to minimise biosecurity inspection requirements–‘but challenges remain to fund and source this equipment.’

The GAO observes that: ‘the Marine Corps risks not having the equipment needed to conduct its mission since, depending on the course of action, it could take years to allocate resources to mitigate this issue.’

Marines training this year will include bilateral and multilateral exercises with the Australian Defence Force and some unilateral training at Defence facilities around Australia. While they’re in Australia, the Marines will conduct about ten major exercises, some with Indonesia, Japan, and New Zealand, for operations ranging from counter-terrorism to humanitarian and disaster relief. The Marine rotation is part of the US Force Posture Initiative, which also includes air force collaboration, which saw 12 US Air Force F-22 Raptor fighters visit Northern Australia for exercises in February.

Whatever US military build-up takes place in Australia under the Trump administration, it’s all moving very slowly at present. The GAO says the Pentagon has completed two infrastructure studies that identify Marine Corps’ requirements for housing and for aircraft support for an expansion of Marine rotations in Darwin. ‘Moreover, DOD officials told us that they began developing a master plan for the infrastructure that will support Marine rotations to Australia.’ But the GAO notes that planning’s still in the early stages for both Hawaii and Australia.