No. As soon as you fully open borders without need for identification of people entering and exiting a country you expose the country to countless threats. Firstly, irrespective of the nationalities concerned, it poses a significant threat to economies. By increasing population, the number of free jobs will naturally decrease as a result of people looking for more work. This impacts people who had been living in said country prior to extras coming in. The focus of countries should be to maintain their integrity and core functionality, not inviting in other countries openly and freely.