Why did congress p the START treaty?

I think they ped it out of desperation. They're shoving law after law down the throats of the public in this lame-duck session while they still can, knowing that the people would not support such laws. Whatever their reasons, I don't like it, and I feel like it makes us much weaker as a country. We should not have to rely on the approval of another country to improve our own defenses, especially one that was our enemy for so long.