All contries must watch all their borders. When someone has to go through two inspections to get to another country it simply doubles the chances of getting caught. it does not guarantee that "no one" meaning to do harm will not get through.
US-Mexico smuggling tunnel found
The US authorities have found a sophisticated drug smuggling tunnel approximately 1,000 feet (300 metres) long beneath the border with Mexico.
These guys were more sophisticated.
I've read that up to 300 tunnels have been found over the years.
In order for this operation from Canada to US to work, there had to be American involvement so, while watching the 'northern border" perhaps someone should be watching the "home front"
If there was no demand, there would be no need to go to these measures to supply the customers
Help, my PC with Windows 10 won't shut down properly
Since upgrading to Windows 10 my computer won't shut down properly. I use the menu button shutdown and the screen goes blank, but the system does not fully shut down. The only way to get it to shut down is to hold the physical power button down till it shuts down. Any suggestions?