Indefinate detention for US Citizens "captured" abroad?

the requirement of military detention does not apply to U.S. citizens,
but it does not exclude U.S. citizens from the authority, the option,
to hold them in military custody.

The only provision from which U.S. citizens are exempted here

is the “requirement” of military detention.

For foreign nationals accused of being members of Al Qaeda,

military detention is mandatory;

for U.S. citizens, it is optional. 

This section does not exempt U.S citizens from the presidential power

of military detention: only from the requirement of military detention.

...this bill codifies indefinite detention without trial.

There is no question that it significantly expands the statutory definitions

of the War on Terror and those who can be targeted as part of it.

The issue of application to U.S. citizens is purposely muddled

— that’s why Feinstein’s amendments were rejected

— and there is consequently no doubt this bill can and will be used by the U.S. Government

(under this President or a future one)  

to bolster its argument that it is empowered

to indefinitely detain even U.S. citizens without a trial.

Glenn