Immigration is a contentious issue that affects both host and home countries. There are several arguments against immigration. It puts economic and social pressures on host countries by increasing costs for social services and job competition. Illegal immigration in particular makes it difficult for governments to plan and provide adequate services. Immigration may also threaten national security and increase crime rates. While skilled immigrants fill labor needs, they also contribute to "brain drain" in home countries. Overall, unchecked immigration can destabilize host countries through its political, economic, and social impacts.