One interesting angle you might take on the Balkans conflict is that of how attitudes have switched in recent years, like this:
During the Serb/Croat war, most of the NATO countries were coming down on the side of the Croats, largely because the Serbs were supplied with a great deal of Soviet weaponry (this is portrayed in the tank simulation game 'T-72 Balkans on Fire' aka 'Iron Warriors'). So in effect it was something of a 'proxy Cold war'. The Serbian position was very anti-muslim, and being pre 9/11, this was not something the US was particularly interested in supporting. Fast forward to the present and it would be interesting to speculate upon whether the vast majority of NATO countries would now pick the same side to support, since they are now all taking a very anti-Islamic stance. Which might make an interesting subject about which to write.
It's also interesting to note that the US tested much of its (at the time) latest stuff over the Balkans, including the supposedly invulnerable F-117 Nighthawk stealth bomber. One of which, the Serbs actually did manage to shoot down with a surface to air missile. The US were also interested in engaging the Serb's MiG-29s which at the time were something of an unknown quantity, so there's a couple of Cold War connections for you straight away. If you do a bit of a search on the internet, you will find some interesting articles about how the Serbs created mock ups of the MiG-29 in order to lure US bombers into its rings of surface to air missiles, and there can be little doubt that much of this was with Soviet backing in order to test their latest air defence systems against the latest US stuff.
Strictly speaking, the biggest proxy Cold War was probably Vietnam, lasting from around 1946, when the French were fighting there immediately following WW2, right up until 1975 when the Americans fully withdrew support for the ARVN after over ten years of involvement. For most of that time, the protagonists were supplied by the Soviet Union and China, versus the West (mostly France, Australia and the US, but also the UK and some other nations). The scope of the conflict might make it difficult to write about concisely however, so it may not be the best choice for a small piece of writing, however, you could choose to concentrate on a small aspect, and there is a wealth of well-documented information on the matter, which is obviously something else to consider.
A more localised conflict upon which to concentrate would be something like the CIA's involvement in the War in Angola. There's quite a lot of source information available on this and it is rarely covered as much as other subjects, so you might win 'Brownie points' for doing something a little different if you choose that.
Chock