Sometimes journal editors (or referees) are observationally very similar to black holes. A paper is submitted, but no review escapes the force of gravity generated by the scientist in question. If the academic who is submitting the paper is well established, (s)he might not be overly bothered by this "black-hole-like effect" and live to see the day. However, in case the paper is submitted by a young scientist who might be applying for jobs, the negligence of an editor or a reviewer might have negative consequences on the career of the author of the paper.
Suppose, by way of example, that a young scientist submits a substantial paper to a high-impact journal reporting on the major findings in her doctoral dissertation. The first review round takes a whole year, despite repeated enquiries to the handling editor, and the editor asks for major revisions based on the detailed referee reports. The author works hard at handling the suggestions from her reviewers, and submits a revised paper. One more year passes and the email enquiries by the author receive no answer from the cognizant editor.
What would be the best line of action for the young scientist in question? Should she wait for a second bunch of reports, which might never come, or would she be best served by withdrawing the paper and submitting it elsewhere? What advice would you give in a situation like this one?