Sen. Marco Rubio, R-Fla., criticized President Obama on Wednesday for failing to act soon enough in Syria, suggesting that it might be too late to influence the conflict in America’s interest.

In a blog post published on his website, Rubio wrote that he had advocated more than two years ago to support non-jihadist groups in Syria.

“Instead, the President chose to lead from behind,” Rubio said. “The result is that the best funded and armed groups in Syria today are Assad’s Iranian-backed killers, Hezbollah fighters aligned with Assad, and rebels with links to al Qaeda.”

Rubio explained that the current situation left the United States with “no good options.”

“Failing to act would further embolden Assad and his Iranian sponsors, leaving the impression that America is feckless and impotent,” Rubio explained. “And a limited attack would do nothing to change the dynamics of the conflict, but could trigger a broader and even more dangerous conflict in the region.”

The freshman senator from Florida proposed that Obama should continue to find “moderate opposition” in Syria worthy of support.

“My advice is to either lay out a comprehensive plan using all of the tools at our disposal that stands a reasonable chance of allowing the moderate opposition to remove Assad and replace him with a stable secular government,” he said. “Or, at this point, simply focus our resources on helping our allies in the region protect themselves from the threat they and we will increasingly face from an unstable Syria.”

Rubio warned Obama not to take military action lightly and insisted that the president make a detailed case to Congress if he chose to act.

“Military action, taken simply to save face, is not a wise use of force,” he said.