To annex resisting British colonies would be in itself an impossible task--physically a much more impossible task than to annex Ireland.
To annex Ireland would be, as a military measure, once command of the seas was gained, a comparatively easy task.

No practical resistance to one German army corps even could be offered by any force Ireland contains, or could of herself, put into the field.

No arsenal or means of manufacturing arms exists.

The population has been disarmed for a century, and by bitter experience has been driven to regard the use of arms as a criminal offence.

Patriotism has been treated as felony.
Volunteers and Territorials are not for Ireland.