You set 1980's developing defensive technology against developed 2010's offensive technology, and conclude that defensive technology is worthless, it is not. It is far better than nothing.
You also miss the entire point of Reagan's SDI. It was designed to use a weapon the Soviets didn't and never could have, and to establish a trust that could be earned by both the US and the Soviets.
It was an unparalleled success.
And Russia sees us as going hard atheist. That also has an effect on how they behave.