The NOAD reports the following definitions for those words.
- state: a nation or territory considered as an organized political community under one government
- nation: a large aggregate of people united by common descent, history, culture, or language, inhabiting a particular country or territory
- country: a nation with its own government, occupying a particular territory
The difference between nation and country is that country refers to the people, the territory, and the government, while nation refers to the people, and the territory.
In the case of federal countries (e.g., USA, Austalia, Germany) a state is just a part of the country; in the other countries (e.g., Italy, France), the state coexists with the country.
Smarmy is a possibility; it means "Falsely earnest, smug, or ingratiating." Also weaselly, in sense "A devious or sneaky person or animal", may apply. An uncommon word that might be relevant is fugacious, "Fleeting, fading quickly, transient", if you expect support to just forget the issue immediately.
More along the line of "empty promise" are words as found in a clique of illusory synonyms: chimerical, fancied, fanciful, fantastic, fictitious, illusory, imaginary, unreal, and similarly for fictive and perhaps for tenuous, "thin in substance or consistency".
Empty promises in the sense of "say what they want to hear" often are called blandishments, which is defined as "flattering speech or actions designed to persuade or influence."
Empty promises may also be evasions, lies, sophistry. Among the senses of the latter are "an argument that seems plausible, but is fallacious or misleading, especially one devised deliberately to be so"; "the art of using deceptive speech or writing"; and "cunning or trickery".
Best Answer
I’d use probability as a quantifiable, mathematical term. If I spoke about probability, I might be talking about numerical odds or chances: e.g. one chance in six or even Bayesian probability. I don’t use possibility in that way, it is more qualitative.
One way to understand the more slight differences in common meaning is to consider the related words impossible and improbable. Sherlock Holmes said:
From that, we can deduce:
Impossible - cannot be done
Improbable - unlikely to be done
Possible - can be done (but may be unlikely)
Probable - likely to be done (and likelihood can be measured mathematically)