“How should I handle a question as to why I would consider leaving an employer that I have been with for a relatively short time? I have been employed with my current employer for 7 months, the previous employer was for 8 years.”
You need to keep your answer short and simple…the longer the answer, the more apologetic it will sound, and the more you will be emphasizing the past instead of the future. Think very carefully about why you left, and how you can put that in a way that doesn’t criticize your employer. Then give a short (1 or 2 sentence) explanation, followed by either what you’ve learned from that (if it was an involuntary resignation, or performance-
“I was hired by XYZ to become a project manager in the IT area. Shortly after I joined them, there was a restructuring, so that the position no longer fit my long term goals. What I’m looking for now is …”
And it will be strongest if the “looking for now” expresses a result you expect to be able to bring to that role or a challenge you can help your target employer overcome.