What factors are needed for a country to have start-up success. We know SV comes from defence money, but setting that outlier aside, what's the winning formula?

What factors are needed for a country to have start-up success. We know SV comes from defence money, but setting that outlier aside, what's the winning formula? China's success would suggest that a huge talent pool and protectionism towards the big US internet companies is a winning move. Anything else?