Even if they suspected it, there would be no proof, so many adopted a don't ask, don't tell philosophy. However, this time, Xinghe had completely broken that contract. She listed Country W and Country C's crimes directly out in the open, and it definitely had caused a good measure of panic for the two leaders.
Other than that, she also made sure the United Nations wouldn't be able to come after her with ease anymore. Even if they still dared, Hwa Xia would counter. Hwa Xia was not a small country, if there was really a war, no one would benefit. Therefore, Country W and Country C had to measure their own capabilities before they openly declared war on Hwa Xia.