As you saw the iron mixed with clay, so the peoples will mix with one another but will not hold together any more than iron mixes with clay.
KJV
And whereas thou sawest iron mixed with miry clay, they shall mingle themselves with the seed of men: but they shall not cleave one to another, even as iron is not mixed with clay.
ASV
And whereas thou sawest the iron mixed with miry clay, they shall mingle themselves with the seed of men; but they shall not cleave one to another, even as iron doth not mingle with clay.