allowing a pipeline to be built isn't really "going out of our way". if it were being subsidized, that would be a problem.
but in general, i think it's better to allow a local oil industry, and properly tax and regulate it, than it is to allow all those profits to go offshore to less-regulated, less taxed foreign operations. people aren't going to stop using oil just because they can't get the locally-produced stuff.
The keystone XL received investment and loan guarantees from government.
Beyond that there's a lot of goverment effort that's needs to happen to "allow" it to be built. Securing right of ways or emininent domain on land it passes through.
but in general, i think it's better to allow a local oil industry, and properly tax and regulate it, than it is to allow all those profits to go offshore to less-regulated, less taxed foreign operations. people aren't going to stop using oil just because they can't get the locally-produced stuff.