It was another call to action on Friday for the South Korean protest movement that had faced down security forces just a month ago to resist President Yoon Suk Yeol’s declaration of martial law.

Those first mass protests got results: Mr. Yoon’s startling declaration of martial law on Dec. 3 was reversed, then the National Assembly impeached him and opened an investigation into whether he had led an insurrection.

But in the weeks since, paralysis and polarization have set in. And that’s what protesters found on the roads outside Mr. Yoon’s official residence.

A mass of Mr. Yoon’s supporters were already there. They had hurried to his neighborhood after being jolted by the news Friday morning of the move afoot to detain him in connection with his martial law declaration last month. Other Yoon supporters had already been there for days, camped out on the pavement near his home in central Seoul, vowing to block any efforts to detain him.

Law enforcement officials retreated after trying for hours to work their way past Mr. Yoon’s supporters and running up against greater numbers of his personal security team. Their warrant to detain him for official questioning went unserved.

Thousands of anti-Yoon protesters rushed in to face off with thousands of pro-Yoon supporters. For his supporters, it was a moment of joy and defiance. For his detractors, one of bitter frustration.