Modi said even a few years ago, when India talked about the threats of terrorism, not many in the world were ready to take it seriously.
"Now that terrorism is knocking at their doors, every government in the world, those who believe in humanity, governments with faith in democracy, are seeing this as one of the biggest challenges," he said in his monthly radio programme Mann ki Baat.
Terrorism, the prime minister said, threatened humanity across the world.
"Terrorism has taken an ugly shape and has become a global threat almost as a daily routine... Terrorism has challenged humanity. It is bent upon destroying humanitarian forces. So not only India but all humanitarian forces will have to keep fighting unitedly to defeat the menace of terrorism," he said in his address.
India, he stressed, was the land of Lord Buddha, Lord Mahavir, Guru Nanak and Mahatma Gandhi and gave the message of love and non-violence to the world.
Modi said while November 26 was observed as Constitution Day, the nation could not forget that on this day nine years ago, terrorists launched attacks across Mumbai.
"The country remembers and bows to those brave citizens, policemen, security men and each one who lost their lives then. This country can never forget their sacrifice," he said.
He also recalled the role of the Indian Navy in war and peace ahead of Navy Day to be celebrated on December 4.
While most navies of the world allowed women on their warships only in later years, a large number of women played leading roles in the Chola Navy, about 800 or 900 years ago, he said, referring to the Chola Empire.
He said while many recall the role of the navy in war, the force had also played a key part in extending humanitarian aid to India's neighbours.
On the Armed Forces Flag Day observed on December 7 every year, Modi said this was a day to take pride in, and to show respect to the country’s armed forces.
He said between December 1 and December 7, a campaign is being organised to spread information about the armed forces.
'Throughout the week every one, old or young, should wear the flag... Experiences and acts of valour of those from the armed forces...can be posted on a hashtag for the armed forces flag day (#armedforcesflagday),' he suggested.
He said this was also an occasion to collect funds for the welfare of jawans, for dependents of those killed and the rehabilitation of those injured during wars.
He pointed out that cashless donation was also possible.
To mark World Soil Day on December 5, Modi wondered what would happen if there was no fertile soil in the world.
"The very thought is dreadful. There will be no soil, no plants and trees will grow... Serious damage is caused because of an excessive use of urea. Can our farmers... resolve that by 2022, when we complete 75 year of our independence, they will cut down the urea usage to half of what is being used presently," he asked.
Wishing people on the occasion of Id-e-milad-un-nabi, to be celebrated in the coming days, he said in the new year, people should forget their sorrows and remember their joys.
"Can’t we share five of our positive life experiences of the past year? Come, let us share our positive experiences with #PositiveIndia on the Narendra Modi App or MyGov portal.
"If you remember positive events, then you will be in a mood to do good around you," he said.
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