A refugee crisis happens when a situation threatens to create too many refugees for the country that takes them in. The most common reason is war and conflict, but natural disasters (floods, earthquakes, hurricanes, mudslides) and climate change are also causing people to leave their homes and seek asylum in other countries.
When this happens, it is often because their home country has proven they cannot protect them or their communities from threats like bombs, prison, rape, the breakup of their family, and other physical or psychological harm. This is why they are seeking asylum in a foreign land and are protected by international law, which states that governments must allow them into their territory.
While there are some countries that take in large numbers of refugees, most do not. This is because they may view the refugees as a threat to their stability. They may fear destabilization or see them as a threat to their political power, especially when they share ethnic or religious characteristics with local populations that are already in conflict with each other.
In addition, refugee crises can become a vehicle for scapegoating and manipulation. This is particularly true when a refugee population grows large enough to capture the attention of national leaders, who are often forced to address the problems that result from displacement without being able to focus on the underlying conflict that created it in the first place. This can make the crisis appear more permanent, and it can distract from conflict resolution efforts.