Why were american troops critical of their south vietnamese allies?

they did not seem to fight as hard as their north vietnamese and nlf counterparts.
they could not speak english.
they did not know how to fly planes.
they were anti-communist.

under god i have placed my chiest strentgh and the safe guard to my loyal subjects

answer: this is because archeologists keep finding artefacts and ancient ruins dated more than 10000 to 15000 years, date around scientists said humans discovered language; which is at least mysterious as scientists always have said that is necessary to have a language to have architecture and some basic maths.

explanation: brainlest