Two powerful countries being in agreement is usually a good thing. Tensions amid the United States and Russia would not be good for anyone, as they are still the two nuclear superpowers of the world. An arms treaty would ensure lasting peace--especially amid rising tensions with the Ukraine and Russia.
The GOP should endorse, support and ratify any strategic arms reduction treat (START) with Russia. The reasons are manyfold, but the most important is to increase world security. Fewer nuclear weapons means a more peaceful planet. World superpowers learned during 50 years of the Cold War that the only way to be free of nuclear weapons is to rid the world of them. We have a global economy now and every country is important, so reducing nuclear weapons makes everyone safer.
I do not believe the Republican party would be wise in endorsing the strategic arms treaty with Russia at this time. Given the fact that Russia is entering the Ukraine at this time we don't know exactly where they are going to stop. I do not think there actions warrant our interference, however we shouldn't be working on treaties with them until its clear their intentions are pure.
You do realize, I hope, that political parties are not in charge of ratifying (or endorsing, or whatever you want to call it) treaties? That's the power of Congress as a whole. And thank God, because the last thing we should do right now is sign any treaties with Russia.
No, the Republican party should not endorse the strategic arms treaty with Russia, because there's no way that Russia would agree to it. Russia is practically about to take over the Ukraine. We certainly can't trust them to follow and arms treaty with us. We need to be skeptical of the old red USSR.