How crippling are U.S. sanctions on other nation's economies throughout history?

Very much so. Let me offer you a perspective from where I come from, Vietnam, a country that suffered tremendously and was on the verge of economic collapse after 30 years of US sanctions. In 1994, President Bill Clinton formally normalised relations between the two countries. Foreign investment started flowing in and the country’s economy has been changing rapidly ever since. There was an immense sense of optimism and gratitude. Bill Clinton was warmly and enthusiasticlly received when he visited Vietnam in 2000. We have benefited greatly from this event and opening up trade to the world.

Some historical background on the US sanctions, which is quite fascinating in and of itself:

Towards the end of the Vietnam war, the Paris Agreement in 1973 called for a ceasefire and withdrawal of all US troops and the eventual reunification of the country through peaceful means. However, subsequently, the North forces launched the invasion of the South and reunited the country by force. The North Vietnamese leaders were giddy in their glory after defeating the world’s super powers and pursued the establishment of diplomatic relations with the US, demanding $3b in reconstruction aid. The US neglected the call for normal relations and demanded a full accounting of MIA personnel. Washington continued Nixon’s 1964 trade embargo to all of Vietnam and all bilateral trade was prohibited.

Washington was also in the process of normalising relations with China after Nixon’s visit in 1972. Vietnamese leadership had always been shrewd in playing the Soviets against China or China against the US. They formalised the ties with the Soviets to counterbalance an increasingly unfriendly China. It did not win favours from the Americans.

In this same period, the workers of the world were hardly in solidarity. Cambodia under the murderous Pol Pot regime invaded South Vietnam. Vietnam responded by invading and occupying the country after defeating the regime. China did not want Vietnam to become too arrogant and dominating in Southeast Asia, and swiftly invaded the norther border of Vietnam to teach a lesson in 1979. [1]

After the fall of Phnom Penh, Prince Norodom Sihanouk accused Vietnam of violating Cambodia’s sovereignty at the UN Security Council meeting[2]. He demanded all UN countries to suspend aid to Vietnam and not recognise the Vietnamese-installed regime. Several countries called for a ceasefire and withdrawal of Vietnamese forces from Cambodia but with strong opposition from the Soviet Union and Czechoslovakia, the resolution was not approved. The UN decided to recognise Democratic Kampuchea as the legitimate representatives of Cambodia despite the Khmer Rough’s genocide. Vietnam was strongly condemned by a pro-Chinese coalition led by the US and ASEAN. The United States imposed stringent economic sanctions, which included a trade embargo, and blocked financial assistance to Hanoi through the IMF and the World Bank. It also kept nations such as Japan from providing help.[3]

Vietnam’s decade-long occupation of Cambodia turned the country almost friendless apart from the Soviets and the socialist block. In the 1980s, Vietnam’s economy was near collapse due to economic mismanagement and a large military budget spent on Cambodia. Vietnam was heavily reliant on economic aid from the COMECON and loans from international agencies of the capitalist world. Moscow was Hanoi’s largest trading partner. Relations with China were icy. The only Western country that provided Vietnam with developmental assistance in the Cold War era was Sweden.

The Communist party were arrogant and ignorant on how to run the economy. Industries were nationalised, inefficiently run and stagnated. Salary was extremely low and goods were scarce. Most people had to take up odd jobs to supplement their incomes. My parents’ generation still remember with much horror the poverty of the time. My aunt and mother used to knit and sew clothes until the wee hours because of starving wages for state employees.

Collective farming was disastrous and food production plummeted. The South which used to be prosperous and the bread basket of the country also suffered from food shortage, which had been unheard of. Food shortage was so severe people had to mix rice with animal feed from the Soviet Union. Necessities and food items were purchased with ration coupons. The ration for an average family was about half a kilogram of meat, a kilogram of salt, 1.5 litres of fish sauce a month. Every member of society received a ration depending on their position in the state sector. Sometimes, wages were paid in goods (bicycle, rice, meat, cloth etc.). Party members often received much more generous rations than ‘commoners’ (6 kg vs 0.5 kg of meat/month). Long queues at state-run department stores were a common sight. Food, machinery and raw materials were all reliant on the Soviet Union and other socialist countries. Inflation was high.

The queue at a state-run store

Pumping and fixing bicycles, a common odd job to supplement income

People were poor and life was miserable

A ration coupon for one kilogram of meat for a month

Private enterprise was forbidden, my parents recount stories when they brought to the city some chickens or eggs as gifts from relatives in the countryside, they would be confiscated if caught by the police. The state distributed dozens of necessity goods such as food, rice, fuel, textile, batteries, soap, paper, cement, bicycle tires. Goods was not traded freely on the market or moved from one province to another. Exchanges in cash were limited, so even people with money still sometimes went hungry because there was nothing to buy. Supermarkets or markets did not exist. Small businesses that are ubiquitous today were almost non-existent or operated illegally.

Sales people at state-run department stores were like kings and they often reserved the best food for their relatives or friends. Most people received very low quality goods. My family raised chickens and pigs in our backyard to supplement our pathetic diet. Petty thefts were common. The hunger and despair crushed human dignity and conscience. There was a joke that the burned rice at the bottom of the pot in collective kitchens was often given to pigs. Sometimes people stole it because they were too hungry. If they were found out, they were made to apologise to the pigs! Many people tried to flee the country. There was a saying “if the power posts had legs, they would try to leave too.” The harshness and despair of that period is unimaginable to young people today.

Profound cynicism about life’s hardships and failed promises was widespread. We also stagnated culturally and were a completely closed society with very little cultural exposure to the outside world (We didn’t have Coca Cola or Western movies/music until the mid 90s). The economic hardships were caused by a combination of international isolation and catastrophic economic policies. Vietnam was one of the poorest nations in the world, probably not different from North Korea today.

After the collapse of the Soviet Union, Vietnam had to explore new ways to end its isolation. There were some concessions on both sides towards the end of the 80′s and the embargo was eventually lifted in 1994. After normalisation of trade relations, bilateral trade between the two countries has grown rapidly. Goods are abundant nowadays and exposure to external cultural influences is much greater.

So yes, sanctions by the US can be devastating, both economically and culturally.