USS Boxer. Flickr/U.S. Pacific Fleet. Some rights reserved.The United States-led air-war against ISIS has now lasted for 20 months, with the Pentagon reporting that its 10,000 air-raids have killed 28,000 of the movement's supporters. There is, however, growing evidence that ISIS leaders had anticipated such an onslaught, and that as long ago as 2014 – when their advance across much of Syria and Iraq accelerated – they had begun preparing for attacks against western targets, not least in Europe (see "The war on terror: an interim report", 7 April 2016).
In the same period, attacks by ISIS and its affiliates have intensified. The wide-ranging incidents include those in Tunisia (the Bardo museum in Tunis and the Sousse beach resort), several bombings in Turkey, the destruction of a Russian Metrojet airliner departing from Sinai, Egypt, and the multiple assaults in Paris and Brussels.
ISIS has certainly been pushed back too in Iraq and Syria, although the picture is mixed. Iraq's army has found it very difficult to make any progress against ISIS forces outside Mosul, and the group has actually retaken some towns in northern Syria.
A sketchy outline of these latter developments is available in parts of the media. But a more detailed picture requires scouring the more specialist military publications as well as the conventional press. What emerges is that the United States is quietly expanding the forces it is deploying against ISIS, and that enhanced, multi-level war – both in the air and on the ground – is its strategic choice.
On air and ground
Three indicators provide a strong lead in this direction. The first is the recent decision of the US air force to base B-52 strategic bombers in the region. A flight now operates out of al-Udeid in Qatar, probably the largest air-base of any kind in the Middle East and home to some 10,000 US military personnel. The B-52s are from Barksdale air-force base in Louisiana; they replace B-1B bombers that have been used repeatedly in air-raids against ISIS forces in Kobani and Ramadi.
From the few accounts available from independent observers, on the limited occasions when ISIS forces have been evicted from parts of towns such as Kobani and Ramadi, USAF strategic bombers have been used freely. The results entail large-scale destruction of urban districts.
The second and third indicators refer to the ground war, and involve both special forces and marines. On the former, president Obama is reported to be considering adding a further 250 JSOC (Joint Special Operations Command) personnel to existing contingents opposing ISIS in Syria. On the latter, the marines' forward artillery base south of Mosul – now called Firebase Bell – is the centre of frenetic activity every day, with close to 200 marines operating four M777A2 long-range howitzers. Firebase Bell has already been targeted by ISIS, which managed to kill one marine and injure several more in a rocket attack.
The marines' main campaign weapon is its standard 155mm field gun, the M777A2, which was originally developed by VSEL (now part of BAe Systems) at Barrow-in-Furness. The use of titanium rather than steel reduces the weight by a third compared to the M198 it replaces, and allows it to be transported both by a range of helicopter types and by the Osprey tilt-rotor hybrid. The gun's range, using a standard shell, is 24 kilometres, but fitted instead with enhanced base-bleed projectiles this increases to 30 kilometres. This means that a single firebase, with each gun firing two rounds a minute, can cover an area of, respectively, up to 1,250 square kilometres or over 2,000 square kilometres.
The Pentagon is now preparing to supplement Firebase Bell, either with new bases or ones mothballed when American forces withdrew from Iraq in 2011. Washington believes that such facilities will be required if the Iraqi army is to make any progress against ISIS forces in Mosul. Moreover, the stalling of the Iraqis' campaign makes it more probable that regular US combat-forces, as distinct from special forces, will again become a feature of the war.
The military pattern
All this suggests that US forces are becoming steadily more involved in a full-scale ground war. A further indicator here is the deployment of a substantial marines force to the Persian Gulf, which is nearly twice the size of the unit it replaces.
The 13th Marine Expeditionary Unit comprises three large amphibious warfare ships: the USS Boxer amphibious-assault ship, the USS Harpers Ferry dock-landing ship, and the USS New Orleans amphibious-transport dock. Together around 4,500 personnel are involved. The air wing includes AV8B Harrier strike-aircraft, MV-22 Osprey tilt-rotors and UH-1Y Venom helicopter.
Its purpose was rather bluntly described by the air-group commander, Captain Keith Moore: “I look forward to leading the force as we execute missions and tasking at the pointy end of the spear of the 5th Fleet”. It is some “point”, given that this expeditionary unit alone is more than half the size of the entire UK Royal Marines Commando force.
The intense air-war against ISIS since August 2014 is now evolving further into a ground war, whatever is being said openly and however little public debate there is. The latter may change, as the prospect of "boots on the ground” increases. But by then it may be too late, as an escalating war with all its consequences will be in full swing.