Every elected official who is eligible for reelection spends a great deal of time raising funds and campaigning for the next election while still “serving” in office. Also, how an action might play politically in the future often leads to irresponsible decisions in the present.
A single-term limit, as opposed to term limits in general, addresses the above issues, but it also forces officials to return to and live in the country they shaped in part, rather than continuing to be sheltered by the special privileges of their office and not facing the consequences of their decisions. A six-year term allows for one year to learn a job and five years to do it well. Such an amendment should also specify that no elected official can campaign for another elected position while serving in office.