McKinsey has Global Growth Model scenarios out to 2022 bounded by emerging markets' growth rates (between 3 and 7 percent per year from 2013 to 2022) and advanced economies' growth at 1 to 3 percent annually. These growth rates define four broad-based scenarios: Global Growth Renewed, Advanced Economies Rebound, Emerging Economies Lead, and Global Lost Decade.
The scenarios suggest dramatic shifts in defense spending in absolute terms. Defense spending in the BRIC countries and Saudi Arabia will increase significantly in all scenarios—from roughly $290 billion in 2011 to between approximately $550 billion and $830 billion by 2022 (in constant 2011 dollars). The fate of the United States and its major treaty allies' defense spending is mixed, however. When the major developed economies fare well, their combined defense spending increases from a little over $1 trillion in 2011 to more than $1.4 trillion in 2022; when they fare poorly, in the Global Lost Decade and Emerging Economies Lead scenarios, their combined defense spending falls below $1 trillion by 2022.
China, Russia, India and Saudi Arabia would #2 to #5 in military spending in 3 out of 4 scenarios
Read more at NBF