Beijing residents on Sunday shared photos and video clips of military planes training for a parade in the sky.

As many of them show, some of the planes trailed colored smoke as they flew, while some flew in formations making the number 70, to mark the People's Republic of China's 70th birthday, which falls Oct 1.

Sunday's hottest hashtag on Sina Weibo, China's equivalent to Twitter, referenced late Premier Zhou Enlai, the first Premier of the republic. At the founding ceremony of the nation 70 years ago, with only 17 planes that participating in the parade, Zhou ordered them to fly twice to finish the ceremony.

The hashtag features the sentence, "Premier Zhou, we have enough planes now and they do not need to fly twice any more."

Westerners might find it hard to understand, but behind that sentence is the 70-year struggle of the Chinese nation. When the republic was newly founded, there was still a significant number of territories to be liberated and New China had barely enough air and naval forces to protect itself.

According to historical records, four of the 17 planes participating in the ceremony were fully loaded with bullets, because there were fears that air forces of the Kuomintang, which was losing its power, could bomb Beijing in revenge.

A weak industrial capacity had already left the Chinese people painful memories.

From the Opium War in 1840 to the Chinese People's War of Resistance against Japanese Aggression (1931-45), Chinese soldiers had to counter better-equipped enemies almost every war, which resulted in more sacrifices and casualties than the enemy.

In the war against Japanese aggression, part of World War II, the casualties of the victorious China were 35 million, much higher than that of the defeated Japan. It was lack of industrial capacity that caused these additional sacrifices.

Now 70 years later China, as the second largest economy of the world, can finally equip young soldiers to defend its people so they do not need to fight tanks with rifles.

China can finally proudly defend its people's lives and security.

Of course, that achievement would not be possible without the struggles of New China's founding fathers 70 years ago. Had they not achieved national independence and unity, China might still be a big, weak agricultural country today, not a major global player.

That's why, upon seeing the aerobatics of these military planes, so many people were moved to remember Premier Zhou.

The best way to honor their efforts is to continue building the nation and realizing the great national rejuvenation, so that the days of weakness will never return.