Yes, to a degree, it is necessary for country to prioritize its own citizens while being over global cooperation

The reason being that presumably the ability to assist global crises or other populations, you require a fairly strong and stable country and citizenry. If you over prioritize exterior needs, at the cost of your internal requirements and well-being, you will no longer have the strength and structure to help anyone. You do need to put your mask on first, before putting on that of your child's, or you'll both die together. This does not suggest that we should not, or cannot, do both at the same time.