Most of this information is available at the Whitehouse website:
http://www.whitehouse.gov/omb/budget_factsheets_departments1. DOD (Department of Defense): $553 billion
Note: Even adjusted for inflation, this would be the highest base defense budget since WWII.
2. VA (Veteran’s Affairs): $131.85 billion
Mandatory funds: $70 billion
Discretionary funds: $61.85 billion
3. OCO (Overseas Contingency Operations): $117.6 billion
For Afghanistan: roughly $107 billion
For Iraq: roughly $11 billion
4. Homeland security (the part funded outside DOD, that is): $53.5 billion
Explanation: The White House has requested $71.6 billion for “homeland security”—of which $18.1 billion is funded through the Department of Defense. The remaining $53.5 billion goes through various other federal accounts, including the Department of Homeland Security ($37 billion), the Department of Health and Human Services ($4.6 billion), and the Department of Justice ($4.6 billion). All of it is, however, national security funding.
5. Atomic energy defense activities—mostly in the DOE (Department of Energy) budget: $19.3 billion
Explanation: This includes (among other things) $7.6 billion to maintain our nuclear weapons stockpile, $2.5 billion to prevent the proliferation of nuclear weapons (by funding efforts to secure and dispose of nuclear material, to develop technologies to detect and deter nuclear testing and smuggling, and to support international nonproliferation treaties), $5.4 billion for defense environmental clean-up, and $1.2 billion for naval nuclear reactors.
6. State Department overseas contingency operations in Afghanistan and Iraq: $8.7 billion
7. Pentagon “miscellaneous spending”: $7.8 billion
Explanation: For some reason the Pentagon gets this funding for miscellaneous stuff in addition to what it gets from the base DOD budget. I’m still looking for clarification on this.
8. Military aid to foreign countries: $6.6 billion ($3.1 billion for Israel alone).
9. NASA defense activities (satellite spying, etc.): estimated to be $3.5-8.7 billion
Explanation: This is actually more of a guess than an estimate because such things are classified.
10. FBI Counter-terrorism: $2.7 billion
Of course, serious estimates of total defense spending would have to include interest on debt-funded defense activities. That has been estimated to be $109.1 billion or more.