Questions and answers about migrant crisis border issues

Migrants board a bus in Baranjsko Petrovo Selo, at the Hungarian border, northeast Croatia, Friday, Sept. 18, 2015. Croatia has sent buses full of migrants to Hungary just hours after the country's prime minister said it could not cope with the influx. But Hungarian police met the convoy of 19 buses in the border area and refused to let them cross in. (AP Photo/Darko Bandic) Migrants board a bus in Baranjsko Petrovo Selo, at the Hungarian border, northeast Croatia, Friday, Sept. 18, 2015. Croatia has sent buses full of migrants to Hungary just hours after the country's prime minister said it could not cope with the influx. But Hungarian police met the convoy of 19 buses in the border area and refused to let them cross in. (AP Photo/Darko Bandic)

By Associated Press September 18, 2015 4 min read

BRUSSELS (AP) – The movement of tens of thousands of people toward Western Europe is overwhelming border authorities from Greece through the Balkans to Hungary and Slovenia.

Hungary’s crackdown on its border with Serbia has set off a chain reaction. EU member Croatia is the latest to feel the squeeze and said Friday that it lacks the capacity to deal with more than 14,000 people who entered in just two days.

Nations have begun trading accusations about border obligations and other issues as Croatia transports people the long way round, from its border with Serbia to Hungary or further north to Slovenia.

Here are some questions and answers about the legal principles involved:

Q: Who gets to stay and who doesn’t?