The most obvious example of the impact of international relations on the economy is the trade war between the United States and China. I also saw how the national currency fell 2.5 times in Russia due to the aggravation of relations with other countries.
Permanent sanctions can send the economy into recession.
Russia is a country where the economy is very heavily dependent on crude oil and natural gas exports. Almost 75% of the government revenue comes from these sectors. And back in 2014, the crude oil prices dropped by 60% and the government revenue from crude oil exports declined by 80%. This had a very bad impact on the Russian economy, resulting in a recession. And this was what caused the economic collapse and currency depreciation in Russia, rather than the international sanctions. The sanctions had only a limited impact, and without the decline in crude prices they would have become teethless.