The US spent a couple decades covertly aiding guerrilla armies and drug cartels in central and south America against each other or whichever regime we felt like weakening at the time. We had a heavy hand in creating the chaos from which these refugees are fleeing.

You write as if detaining children is the only option. It's not. Just stop doing it. Our country thrived for two centuries without locking up kids. You're telling us now we can't do any better? Sounds like we need smarter people in charge, then.

It’s not about a lack of funds. Children are being abused and neglected as a punitive measure. ICE is taking possessions away from refugees. We can start by keeping families together and allowing them to use the hygiene supplies they traveled with. 

In order for that UN Charter law to be applied the USA would have to have a Safe First Country Aggrement with Mexico. It does not currently have that, so seeking asylum in the USA is completely legal. And in any case, according that UN rule does not apply to unaccompanied minors (which some of those seeking asylum…

The only way to seek asylum is to present yourself at a port of entry, AKA show up at the border. The people being detained are following that process.