If the border with Laos had been closed and North Vietnam had not been able to operate in the country, the communist side would not have been able to stock up on resources, men, ammunition, weapons, food and medicine through the HoChi Minh Trail.
Therefore, the forces of the North that were fighting in South Vietnam would have been out of supply, and their defeat would have been imminent.
Gorbachev pursued glasnost and perestroika reforms in part because the war in Afghanistan had drained the nation's resources. Mikhail Gorbachev, as known as the former General Secretary of the Soviet Union (Russia), noticed that there has been a huge decrease in their resources. They were fighting a war in Afghanistan, and used all of the nation's resources to help them win the war. Since they used most of their resources, they didn't have much to help the economy, so if they don't get enough resources back, the economy would fail. Because of this Gorbachev made a movement called "perestroika" to help get back the nation's resources. What this movement did was let the government speaker, or have a conversation, about the issues that are going on in the economy, and see if there could be a way to solve it.
The declaration was a laundry list of affronts to the colonies by King George III, wherein Jefferson et.al. argued that since the monarchy did not treat the colonists like other Britons, the colonists had the right to form their own sovereign nation. It was also intended to justify this action to other monarchies to prevent them from helping Britain retain the colonies under the doctrine of Intervention. So it helped to justify the war domestically and internationally.
