I pay tribute to the hon. Member for Merthyr Tydfil and Rhymney (Mr Havard) both for his service on the Defence Committee and for having set out very clearly the two central questions in the debate about defence spending: first, the focus on threat—what is the threat we face?—and secondly the fact that these threats are now concurrent.
The reason we need to spend at least 2% of GDP on defence is that the entire defence planning assumptions created in 1998 and in 2010—those in the national security strategy and strategic defence and security review, leading up to Future Force 2020—have been bypassed by events; they no longer hold. As the hon. Gentleman pointed out, the world has changed fundamentally, and those assumptions—this is why we cannot just tweak the NSS or be complacent about the SDSR—were essentially developed on two bases. The first was that the cold war had ended. The NSS stated again and again that the cold war had ended and that we needed to be much bolder about getting rid of cold war capacities.
The second assumption was that what we will be doing in the future is the same kind of things that were happening in 2010—primarily Afghanistan. Absolutely central to the SDSR was the idea that what we need is something called “enduring stabilisation operations”.
That meant that we were planning to go into a single country—or, at most, in US planning, two countries at a time—for a very long time with a large number of troops. The concept was: Iraq and Afghanistan; 100,000 to 130,000 troops on the ground; Britain contributing 10,000 of those troops—or, in the latest Future Force 2020 structure, 6,600 troops. All our brigade structures were set up to sustain that. The idea was that we would have force structures to keep 6,600 troops on the ground for a decade.
The world has changed completely, however, and as the hon. Member for Merthyr Tydfil and Rhymney pointed out, it has changed in two ways. First, we have a return to a threat from a conventional state with an advanced military capacity—Russia. That is a major change: it reshapes the entire assumptions from 1998 to 2010. Secondly, as the hon. Member for Merthyr Tydfil and Rhymney also pointed out, we now have concurrent threats that are not just happening in one state at a time. General Sir Peter Wall pointed out that the basic assumption of the SDSR was for a benign security environment. We had come out of Afghanistan, and we assumed that there would not be anything looking like Afghanistan again very soon. Of course, if we look around the world, we see developments—I shall deal with them in greater detail later—in Yemen, Libya, Syria, to some extent in South Sudan and certainly in western Iraq and still in Afghanistan. We are seeing exactly the same threats, but they now happening in half a dozen countries at one time.
Let me deal briefly with this threat assumption. We need more defence spending because we need to deal with those two things: the conventional threat from Russia and the concurrent threats from all the fragile states that are currently harbouring Islamist groups, terrorist groups—groups that appear to threaten the west. Dealing with this requires imagination, new force structures and spending.