The prince, who will hang up his army boots next month, told The Sunday Times: "I dread to think where I'd be without the army. You can make bad choices in life, some severe, but it's how you recover from those and which path you end up taking.
"And the army has done amazing things for me. Bring back national service."
The newspaper reported that Harry would even encourage his niece and nephew, Prince George and new arrival Princess Charlotte, to get involved with the British army.
The UK's National Service Act imposed military conscription during World War II and was extended afterward before being abolished in 1960.
But according to data from the U.S. Central Intelligence Agency, military service is still compulsory in about 72 countries
, with a large proportion in Africa, Asia and Europe.
For example, in Austria, a referendum in January 2012 saw a majority of Austrians vote for retaining a two-year conscript service obligation, with a registration requirement at age 18.
While many countries allow women to volunteer to serve, Norway decided last year to conscript women on an equal basis with men
from the age of 19.
In Israel, Jews and Druze are required to serve in the armed forces from the age of 18 and both sexes are obliged to register.
North Korea "voluntarily" extended its national service
due to a shortage of troops in November 2014, while neighboring South Korea is conscripting more women into its armed forces.
In Lithuania, a new law passed in March reinstated national service on a limited basis for men aged 19 to 27.
Some countries, such as China, Indonesia and Mali, allow selective conscription, requiring men to join the military providing they fit certain criteria.
Other nations, such as Argentina, Portugal and Ethiopia, have the power to enforce national service if there is a shortage of troops. And countries such as Spain and Sweden have kept conscription as an option in a national emergency.
Conscription has also been abolished in a number of places, such as Germany, Bulgaria, Romania, Kuwait, Jordan and Ecuador.
Since the prince's impassioned support for the national service, there have been mixed reactions on Twitter, leaving some a little disgruntled.
"Tell you what, Prince Harry: we'll do National Service if you and your family do proper jobs (for life), and live only off the wages," tweeted Simon Price.
But a few others can see the benefits.
"Al the Gooner" tweeted, "Bring back National Service for all 16-19 yr olds."