today I read the news that Iran has warned about "more serious revenge" against the United States. such statements are not some kind of joke and what exactly they can do?

I believe that 2020 began very poorly if you look at it from a political point of view.
If the disagreements between the US and Iran will continue, this could end badly. How will this news affect the market? can they start to sharply raise bitcoin at the price? if bitcoin will grow fast, then altcoins will be even worse

Before they can make actions against US, they have to deal with their people first. As far as I know, Iranians are protesting about the current situation and they do not want war.
Ain't a good start for 2020 but this leads for the price to pump. This disagreement between the two will lead to a pump for the price of bitcoin. There's still no action made against each other but they can be preparing for it, as well those people who are preparing and investing in crypto to secure their money.
It seems to me that indeed for many Iranians it is cryptocurrency that is a very good way out of this situation in order to save their money and try to withdraw their money from this country. I do not know the exact information, but I can quite believe your words that many Iranians are protesting against the current situation and against the actions of the government, since everyone wants to live in peace, and not to fight the whole world. Now the situation is such that Iran will be like a person of Non Grata, in addition, the United States has again strengthened and adopted a new package of sanctions against Iran, after Iranian air defense shot down a UIA civilian plane.