The example is the attack that the US has been using Ukraine to do to Russia since 2014 and even earlier. It looks like a test. But Russia figured out when it was really war, and they did something about it in Feb. 2022.
As if "testing" other countries through the use of violence to figure out what they are capable of was not bad enough and could escalate into a full hot war between one another...
It kind of reminds me those times when the United States used to test a lot countries like Cuba and Venezuela with their military incursions and plans, to see what they were capable of, in the end the United States lost control over Cuba and sanctions standing today are rather a collective punishment on the cuban people (many of them do not have anything to do with communism) and in the case of Venezuela: since the USA tries to kidnap and assassinate the former president of the country, it only made the left leaning people of the country to become more anti-american and anti-imperialistic.
When those tests on other nations backfire, they do it in an expectacular way, don't they?