What happens when the "locally-elected" representatives of the U.S. Congress try to break out of their provincial hamlets and -- Walter-Mitty-like -- attempt to enter the big stage of international affairs to play President and to conduct foreign policy?
The immediate result, as we see from news reports, is the quick souring of world politics on an unprecedented scale, even among allied nations. See the BBC News piece at Russia's Putin orders 755 US diplomatic staff to be cut.
Nothing the Trump administration may have done wrong in the last six months compares in stupidity with this inexcusable Congressional overreaching of its Constitutional legislative powers, which are normally subject to the doctrine of the "separation of powers" that marks the executive, judicial and legislative branches.
Without ANY probative evidence that the Russian government actually interfered in the past U.S. Presidential election, Congress has usurped the President's Constitutional duties and has decided to go ahead with stiff retaliatory sanctions against Russia anyway -- usurping thereby the foreign policy sphere of the President -- and even threatening U.S. allies in THEIR economic relations with Russia if they do not toe the U.S. Congressional line.
Normally, the President makes foreign policy, not locally-elected foreign-policy-clueless local State representatives.
No sane nation conducts foreign policy through parliaments... and for good reason not. So, what now? Another Act of Congress in retaliation ... etc. etc.? Surely the people in Congress jest!
This Congressional usurpation is all the more difficult to understand given the widespread ignorance among voters and their locally-elected State representatives about all things foreign.
In the USA generally, try finding any news beyond even greatly limited local happenings on your local TV channels or radio stations. The rest of the world is mostly invisible somewhere "out there".
As one U.S. cashier in the dark fields of the republic said to a customer (true story): "Y'all talk funny. Where ya from?" Answer: "London". Reply: " Is that near England?"
That and similar knowledge gaps are not a good information basis for foreign affairs. And that is why parliaments are not responsible for foreign policy.