  Starting from 6D superconformal field theories (SCFTs) realized via F-theory,
we show how reduction on a circle leads to a uniform perspective on the phase
structure of the resulting 5D theories, and their possible conformal fixed
points. Using the correspondence between F-theory reduced on a circle and
M-theory on the corresponding elliptically fibered Calabi--Yau threefold, we
show that each 6D SCFT with minimal supersymmetry directly reduces to a
collection of between one and four 5D SCFTs. Additionally, we find that in most
cases, reduction of the tensor branch of a 6D SCFT yields a 5D generalization
of a quiver gauge theory. These two reductions of the theory often correspond
to different phases in the 5D theory which are in general connected by a
sequence of flop transitions in the extended Kahler cone of the Calabi--Yau
threefold. We also elaborate on the structure of the resulting conformal fixed
points, and emergent flavor symmetries, as realized by M-theory on a canonical
singularity.
