Is the sentence correct? the world has changed

im trying to explain that we dont need to buy any more weapons since we use brains nowadays. It is a economy wars. Hackers started to spread the viruses to the rival contries to make their economic suffers. Thus, reducing the GDP.

my sentence:

The world has changed, people dont physically hurt each others anymore.

we dont need to train our troops to be proficient in using weapons because the world has changed. Teach them network security or how to face hackers case by case.