One defense of the Divine Command Theory of Ethics is that if ...

[NClaborn]

One defense of the Divine Command Theory of
  Ethics is that if there were no God, then there would
  be no morality.

 
  What will be an ideal response?

Question 2

As imagined by Ignatieff, a global ethic would reach
  out to common ground where it exists, while agreeing
  to disagree about the claim that ethical conduct must
  be derived from a spiritual or religious duty.

 
  What will be an ideal response?

[welcom1000]

Answer to Question 1

Without God as a source for morality,
there would be no eternal, absolute or objective basis
for morality. Additionally, without a divine judge who
gives out punishments and rewards in the afterlife,
there would be no motivation to be ethical.
An argument against this theory is religious diversity.
Given the broad array of religious beliefs throughout
the world, and even the diversity of beliefs within each
religion, it is difficult to determine which truly reflects
the divine command.
It is inaccurate to say that if there were no God, then
everything would be permitted. A number of ethical
theories provide reasons and justifications for ethical
principle without reference to God.

Answer to Question 2

The global ethic would be based on reasoning and justification of ethical ideas and behavior.

[NClaborn]

Excellent

[bdobbins]

Great answer, keep it coming