Why was it so difficult to create the suez canal?

Finished in 1869 The Suez Canal connects the Mediterranean sea and the Red Sea. It took 15 years to complete and was setback multiple times by political disagreements between the countries involved, shortages of workers, and a cholera outbreak that killed may of the workers. Britain strongly oppose the construction of the canal even though they bought 44 share in it as soon as it was completed.