Retired U.S. Navy SEAL Jocko Willink has spoken out on the devastating situation in Afghanistan this week, as many are seeking to flee the country after it fell into the hands of the Taliban militant group. Willink took to social media to share his thoughts on the matter.

"There is evil in the world. If given the opportunity, it will grow in strength and power," Willink, who is also an author and podcaster, wrote on his Facebook page. "The only thing that can stop evil is people willing to stand and fight and sacrifice to destroy it."

"When there is no will to fight, evil will win."

Willink emphasized that when there's no will to confront evil, "Innocent people will suffer" and "Darkness will expand." And though the "battle is fraught with blood and tears, failure and defeat" and "anguish and loss," the "good and the brave souls will hold the line" and see that "Righteousness will prevail."

Nevertheless, there is a battle that needs to be won, and people need to fight continually and fervently for freedom because "freedom is not free."

Reiterating that "freedom is not free," Willink argued that there are a few individuals who have the "will to fight," just as he and his comrades once did. Now, however, he is seeing a lack of that same fighting spirit he once witnessed. In fact, U.S. Defense Secretary Lloyd Austin may share the same sentiment.

According to CBS 58, Defense Sec. Austin said that the Pentagon had already been planning for several "outcomes" following the withdrawal of U.S. troops in Afghanistan. However, the 68 year old retired U.S. Army four-star general said, the "lack of resistance that the Taliban faced from Afghan forces has been extremely disconcerting."

Faithwire reported that U.S. Navy SEAL Rob O'Neill, who was one of the men who eliminated al Qaeda leader Osama bin Laden in 2011, criticized the Biden administration and U.S. Army Gen. Mark Milley for mishandling the entire situation, even calling for Gen. Milley's resignation on Twitter.

On Monday, President Joe Biden ordered 1,000 more U.S. soldiers to go to Afghanistan, bringing the total number of American troops to 7,000 to assist in the withdrawal process and ensure the safety of their countrymen. This comes after the U.S. has faced challenges in securing the Karzai International Airport in Kabul, which is a central checkpoint for the U.S. and other countries transporting citizens and refugees via air from the fallen Afghanistan.

What was surprising for many about Afghanistan's plunge into the hands of the militant Taliban is how quickly it all happened. After 20 years under the U.S., 6,000 American soldiers lost, and almost $2 trillion spent on the war, some expected Afghanistan to be able to better defend itself from the Taliban despite experts saying that the U.S.' exit will embolden them to crack down on the Afghans once again.

"While the end result and bloodletting once we left was never in doubt, the speed of collapse is unreal," an ex-intelligence official and U.S. Marine who served in Afghanistan told CNBC. Experts add that it was due to intelligence failures, corruption, money, and willpower that brought down another reign of terror by the Taliban on the Afghan people.