Critical stability issues involving magnetic reconnection that are likely to influence the successful operation of burning plasma experiments are addressed. In particular, we discuss: (1) the stabilization of drift-tearing modes in weakly collisional regimes, with particular reference to nonlinear stability, including neo-classical effects; (2) the present understanding of sawtooth oscillations, in particular the interpretation of peculiar sawtooth features in FTU experiments with pellet

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... on; (3) reconnection near the X-points of magnetic separatrices. This paper is dedicated to Marshall N. Rosenbluth. PACS numbers: 52.35.Vd, 52.55.-s Tearing modes and magnetic islands of finite width It is well known that electron pressure gradient effects influence significantly the evolution of the tearing mode. In particular, in