The resulting reckless pursuit of an unhinged Sanctions War against Russia poses a dire threat to the global economy and domestic prosperity and does so for no good reason of homeland security whatsoever.

With respect to the latter, the sheer facts are overwhelming. So we repeat them with an added total for the respective military budgets: To wit, the economic might of NATO is 29X that of Russia and its combined defense budgets are 18X greater, which tells you all you need to know about the "Russian threat":

NATO: $42.78 trillion of GDP; 945 million population; $45,130 per capita income; $1,200 billion defense budget;
RUSSIA: $1.46 trillion of GDP; 144 million population; $10,300 per capita income; $67 billion defense budget.

Given these realities, why should Washington care about an intramural battle among contiguous peoples and territories that have been joined at the hip for most of the last 1300 years?

The implicit answer is because it's the world's self-appointed policeman and Spanker-in-Chief.

Beyond that, it's apparently due to a putative aggrandizement syndrome. That is, Putin's Russia may be puny in the economic and military scheme of things today, but once it is permitted to acquire a taste for conquest it is certain to grow into a Hitlerian monster.