Measuring bombs dropped is pretty meaningless, although there are some scattered figures. But, damage caused can be quantified more accurately. Comprehensive and comparable data is hard to come by but a collection of data points on both kinds of data that conveys some quantitative sense of the scope of some of these actions is as follows:
U.S. intelligence believes that since September 2015 ISIL appears to
have lost 25,000 fighters in combat (mainly in Syria, Iraq and Libya).
. . . about 45,000 ISIL fighters have died since 2013. It’s believed
that ISIL currently has only about 20,000 fighters available, mostly
in Syria and Iraq. There are a few thousand more in northern Libya,
eastern Afghanistan and Egypt. In all five countries ISIL is under
heavy attack.
From Strategy Page. Air strikes, about 75% delivered by U.S. forces, have been pivotal in destroying ISIS military equipment and bases.
In 2015 the American military, for the first time, used more UAVs to
deliver air strikes than manned aircraft in one combat zone. In this
case it was Afghanistan, where 56 percent of the air-to-ground weapons
used were delivered by UAVs. This is a dramatic shift in Afghanistan
because UAVs delivered only five percent of weapons in 2011. In 2015
UAVs used 530 missiles (mostly Hellfires) and bombs (mainly 127 or 227
kg GPS or laser guided ones). . . . This type of aerial attack has,
since the 1990s, reduced collateral (unintended) casualties (both
military and civilian) to decline over 80 percent compared to previous
methods.
From here.
According to U.S. military officials, there have been an average of 11 air strikes per day since August 8, 2014 when President Obama authorized the beginning of the air strike campaign for a total of 1,600 strikes on 3,200 targets in Iraq and Syria. Much of the military equipment was captured from Iraqi forces in an ISIS surge that began in June. The targets hit have included:
- 184 Humvees
- 58 Tanks
- 700 Other Vehicles
- 28 MRAPs (Mine Resistant Ambush Protected Vehicles) and armored personnel carriers.
- 79 Artillery and Mortar positions.
- 673 Infantry Fighting positions
- 14 river crossing small ferry boats
- 900 ISIS buildings and barracks
- 92 checkpoints
- 23 munition caches
- 52 bunkers
- 259 small oil refineries and storage facilities run by ISIS.
Via Defense Tech. There is more analysis of the impact of, and character of the air strike campaign here noting:
January 6, 2015: On August 8 2014 the U.S. resumed air attacks against
Islamic terrorists in Iraq. Between then and the end of the year over
14,000 sorties were flown, mostly by American aircraft but also by
those from NATO and nearby Arab countries as well as Australia and
Canada. Only ten percent of those sorties result in an aircraft using
a smart bomb or missile. About two thirds of the air operations are
against ISIL (Islamic State in Iraq and the Levant) in Iraq. Half of
the air strikes in Syria have been carried out by American warplanes.
The rest have been flown by NATO and Arab countries. Most of the air
activity has been in Iraq because these operations began in Iraq began
in early August while those in Syria did not begin until late on
September 22nd. Moreover most NATO nations prefer to restrict their
operations to Iraq, so only the U.S. and five Arab nations are bombing
in Syria.
A post at the Lawfare blog summarizes what is known from open media sources about the militant and non-combatant civilian casualties that have been inflicted by U.S. armed drones and airstrikes in Pakistan and Yemen. The key conclusions reached are as follows (tabled abridged to show total ranges without breakdown by source of estimate):
In his widely discussed May 23 speech at the National Defense
University, President Obama acknowledged that “much of the criticism
about drone strikes—at home and abroad—understandably centers on
reports of civilian casualties. There is a wide gap between U.S.
assessments of such casualties, and non-governmental reports.” This
gap is wide indeed. The range of public estimates of civilian deaths
from drone strikes, at the low end, includes the June 2011 statement
by then-White House Counterterrorism Advisor John Brennan that there
had not been “a single collateral death” in a year as a result of
American drones. At the other extreme, the Bureau of Investigative
Journalism, a London-based non-profit organization, puts the number of
civilian casualties between 84 and 193 in 2010, and between 52 and 146
in 2011—the years that together encapsulate the period in which
Brennan said there had been none. . . .
Number of Deaths from U.S. Drone Strikes in Pakistan in 2011
Militant 303 – 575
Civilian 57 – 155
Unknown 32 – 37
Total 392 – 661
Civilian Casualty Death Rate 9% – 34%
. . .
Number of Deaths from U.S. Drone Strikes in Pakistan from 2004-Present
Militant 1,585 – 2,733
Civilian 258 – 890
Unknown 196 – 330
Total 2,039 – 3,570
Civilian Casualty Death Rate
8% – 35%
[In Yemen, from 2002 to the present the] NAF reports between 557 and
760 militant deaths and a total of 596 and 832 total casualties. LWJ
puts AQAP deaths at 349 and civilian deaths at 82. And BIJ’s estimates
are between 15 and 52 civilians killed and 239 and 349 total deaths as
a result of “confirmed” drone strikes—and between 23 and 48 civilian
casualties and 283 and 456 total casualties as a result of “possible”
US drone strikes.
These estimates omit U.S. action in Libya on several occasions (including cruise missiles, and various forms of air strikes), in Somalia and Yemen on a few occasions (mostly drone strikes and strikes with AC-130 gunships, but also via bombing and on one occasion as U.S. destroyer sources missile strike), a significant share of the action in Afghanistan, and the last few years of the Iraq War.
The United States has had troops engaged in conventional war fighting in Afghanistan since shortly after September 11, 2001. The parallel eight and a half year long Iraq War in which 4,487 U.S. solders were killed and 32,223 were seriously wounded, began on Thursday, March 20, 2003 and ended on Sunday, December 18, 2011.
U.S. conventional military involvement in Afghanistan has so far lasted more than fifteen years, although the number of U.S. troops committed to that conflict has varied greatly. In the summer of 2013, the U.S. force was current 66,000 soldiers or so (out of a total coalition force right of 100,000), but for most of the conflict, the force was much smaller than that. The peak size of the U.S. force in Iraq was 165,000 and the peak size of the total coalition force in Iraq was 176,000 (excluding new regime Iraqi security forces) and they were fully withdraw by December 31, 2011 (apart from the 160 Marines who guard the U.S. embassy).