The arms race between the Soviet Union and the United States was at play throughout the Cold War, and many attribute the Soviet Union’s collapse to an inability to sustain the final arms race instigated by Ronald Reagan. This element of competition between the nations involved both nuclear and conventional weapons. Frequently, there was an interplay between the two kinds of forces. During the early Cold War, the United States (having rapidly demobilized after World War II) had to rely on its nuclear weapons in a doctrine of “massive retaliation” to counter Soviet preponderance in conventional weapons. After the Soviets developed nuclear weapons of their own, both powers reverted to a system of flexible response. Underlying nuclear strategy throughout this later era was the concept of mutually assured destruction. This reality made the likelihood of direct superpower conventional warfare unlikely. However, the dynamic of conventional weapons competition had its own paradigm. There, the West relied on superior technology to design higher performing weapons to compete against the massive numbers that could be generated by the Soviets’ command economy.
Time: Mid War
Removed after event: No
Note that it doesn’t matter whether your opponent has met his Military Operations requirements: all that matters is whether you have, and whether you have more than he does. Usually it will be the USSR that benefits from this event, but a US player with ABM Treaty or something similar can often benefit as well.
Assuming that you will not be playing this for the 1 VP (absent extraordinary circumstances), Arms Race thus becomes a rather straightforward choice between 3 Ops or 3 VPs. In this, Arms Race is quite unlike most of the Ops-for-VPs events in that it is actually worthwhile: 3 VPs are often superior to 3 Ops, especially late in the Mid War. (Compare to say, U2 Incident.)
But it depends on how you’d use those 3 Ops: flipping a battleground, in and of itself, is only worth 2 VPs, but denying or achieving a Domination bonus adds an additional 2-4VPs, depending on the region. So for example, if you have no other options, Arms Race is better used for Ops if you are flipping a 1-stability African battleground and achieving Domination as a result. But if you already have Domination, 3 VPs are better than those 3 Ops even if you flip the battleground.
Ideally, you want to wait as long as possible in the turn to decide whether you need Arms Race’s 3 Ops, or if you can get by without and get the VPs instead. Of course, it is never so easy in Twilight Struggle — the longer you wait, the more likely it is that your opponent equals your Mil Ops, at which point the 3 VPs are no longer available to you.
As a rule of thumb, I tend to play Arms Race for VPs towards the end of the Mid War (even holding it between turns if necessary), and early in the Mid War I hold it until the end of the turn and look for an opportunity to trigger it for VPs. In the Late War I will almost certainly take the 3 VPs (and actively try for it).
As a final note, Arms Race is often pretty high up on the list of “lousiest cards to receive through Missile Envy”, despite the thematic appropriateness.