Not surprisingly, America's adversaries are licking their chops right now because President Joe Biden doesn't have much in the way of a backbone.

That was evidenced this week after an Iranian-backed militia group struck a U.S. military base in Syria, multiple times, injuring many and killing one American contractor. Republican lawmakers blasted the spineless president for his soft response, according to Fox News.

While the U.S. retaliatory strikes killed eight of the militia members, the militia groups struck the base again while Biden was making a joint speech with Canadian Prime Minister Justin Trudeau.

U.S. retaliation was virtually non-existent.

"Letting America down"

Sen. Lindsey Graham (R-SC) was one of the first GOP congressmen to slam the Biden administration's actions -- or lack thereof -- after an American was killed.

"President Biden and his national security team are letting America down," Graham tweeted.

He added in a follow-up tweet: "I fear General Milley and Secretary of Defense Austin are not proving to be up to the task of providing the deterrence America needs to remain safe. However, the ultimate blame for the failing foreign policy and military situation we find ourselves in lies with President Biden."

President Biden and his national security team are letting America down.

— Lindsey Graham (@LindseyGrahamSC) March 24, 2023

Graham warned that the weak response will likely inspire the same types of groups to carry out future strikes, which could claim more American lives.

"I fear additional weak and uncertain responses will lead to more American deaths and further embolden our enemies," Graham tweeted.

"Indefensible"

Sen. Tom Cotton (R-AR) echoed Graham's sentiments on the situation, also blasting Secretary of Defense Lloyd Austin.

"Indefensible that American life must be lost before Joe Biden acts. Had he responded in force to dozens of earlier Iranian attacks, this tragedy could have been prevented. @SecDef needs to explain why he isn’t doing more to deter Iran," Cotton tweeted.

Indefensible that American life must be lost before Joe Biden acts. Had he responded in force to dozens of earlier Iranian attacks, this tragedy could have been prevented.

⁦@SecDef⁩ needs to explain why he isn’t doing more to deter Iran. https://t.co/JjvbE9zHWJ

— Tom Cotton (@SenTomCotton) March 24, 2023

Sadly, America is more vulnerable than ever before with Biden at the helm, and even more tragic is the likelihood that this wasn't the last time America's gravest enemies will test the waters.