When placing my essays addressing issues of security and development into historical context I inevitably use the phrase 'the post-Cold War era'. It is important to do this, considering the fundamental changes that took place in almost every aspect of the lives of the human race following the end of the confrontation.
However, it has been twenty years since the end of the Cold War; almost half the age of the 'war' itself. Eventually, due the evolution and progression of humanity from the present to the future, defining the current era as 'post-Cold War' will no longer be analytically or historically useful--it will have moved from the present to the past. We will not be able to define our current era by juxtaposing it against a period of history that is no longer relevant. Though it may be some time before this occurs - a friend and I once worked out that it will be some time yet before the first American President (or indeed any other Western leader) is elected who was not brought up in the shadow of the Cold War.
So what other options are there? Post-modern has the same problem as post-Cold War.
One could possibly make the case for using post-9/11 or GWOT. However, that is a particularly US-centric perspective. And when reading academic analysis published in the late 1990s the 'threat of international terrorism' and various other keywords that are associated with 9/11 security issues pop-up with prescient frequency. So although a shock, it was hardly the foundation-shaking change of world order that the end of the Cold War was, and more a quarter-hour chime in the evolution of order in the post-Cold War era.
What about 'the twenty-first century'? This is the best bet as far as I can see, but suffers from the critical flaw that it is in essence an arbitrarily determined construct of time that bears no relation to actual events.
I don't have any answers - this is a topic that will probably be addressed by those who write the present when it has become the past.