In a paper, I have read that the manifold
$$S^1 \times \mathbb{R}^n$$
with the metric $g=-d \theta^2 +g_0$, where $-d \theta$ is the standard metric on $S^1$ and $g_0$ is the euclidean metric on $\mathbb{R}^n$ always possesses closed causal curves.
Is the reasoning behind this that each closed curve along the unit circle is a closed timelike curve?