I tend to agree the reality is that everyone tries to have advantage over their enemy, it is just nature of things. Nobody wants to play fair.
Now, that being said, I do think Putin is right about arm race. And it is dangerous direction the world is heading in. Why? When every country start investing in nuclear weapon to "defend" themselves, the more advanced countries with nuclear weapons will evolve to seek post-nuclear super weapons. Now, if technological trend in super weapon design continue this way, I would say we are simply racing ourself to our doom faster. As super weapons becomes more deadly, more devastating, eg. before cold war, at the dawn of nuclear age, "reaction time" was several days. During cold war it was cut down to mere hours, and now it's down to merely minutes to call back the nuclear strikes and get back to negotiating table. Soon it will evolve into just nano-second total planetary destruction. There won't be time to call back bomber, there won't be time to even react. It will all be automated "response" to gain crucial "advantage". (incase human operators are dead already). Show down between countries will only happen in nano-seconds between machines, and it's over for everyone.