The linked op/ed actually does a good job at explaining why the current course is unsustainable, and for that reason alone, it's worth a read.
Going forward, one of Republicans' most important challenges will be to explain to the American people why this crisis is real, and why it requires big changes. After all, everyone heard plenty about the "deficit crisis" back in 1992 when Ross Perot was running for President, but (poof!) eight years later (after the tech boom) the government was magically back in surplus, before 9/11.
This time, it's different, and for people to take seriously the reforms being proposed by Republicans, they have to understand why.