Was the Ming Dynasty isolated

Answer 1

Yes.

The explorations which were conducted under the Yongle Emperor were ended because they didn't profit anybody but him. Also, the fleets were extremely expensive and unnecessary because Ming China's main threats came from the Mongolians in the North, not from any sea borne threats. The Yongle Emperor had already conducted many wars and military campaigns during his reign and he was sapping away all the governments money.

Trade was restricted and looked down upon because the Confusion Ministers were gaining a lot of influence and trade went against the confusion doctrine. It was the early 15th century. Ming China was the world's most powerful country and there was essentially nothing they needed or wanted from the outside, "barbaric and uncivilized," world.