We are subject to income taxes in the United States and various foreign jurisdictions. In addition to our significant operations in Israel, we have operations in Ireland, France, the United Kingdom, Serbia, China, Japan and starting from January 2024, in Greece. Significant judgment is required in determining our worldwide provision for income taxes and other tax liabilities. In the ordinary course of a global business, there are many intercompany transactions and calculations where the ultimate tax determination is uncertain. Due to the potential for changes to tax laws and regulations or changes to the interpretation thereof, the ambiguity of tax laws and regulations, the subjectivity of factual interpretations, the complexity of our intercompany arrangements, uncertainties regarding the geographic mix of earnings in any particular period, the potential decision or need to transfer cash or other assets from one jurisdiction to another, potential for tax authorities to challenge the manner in which our subsidiaries' profits are currently recognized, and other factors, our estimates of effective tax rate and income tax assets and liabilities can be incorrect, we could lose the ability to use certain deferred tax assets, we could incur significant additional taxes in connection with a specific transaction, our overall tax expenses could increase, and our business, cash flow, financial condition and results of operations could be materially adversely affected. The impact of the factors referenced in this paragraph may also be substantially different from period-to-period.
For example, a substantial portion of our taxable income historically has been generated in Israel, as well as France starting in 2020. Although our Israeli and Irish subsidiaries historically, and starting in 2022 our French subsidiary, are taxed at rates lower than the U.S. tax rates, the tax rates in these jurisdictions could nevertheless result in a substantial increase as a result of withholding tax expenses with respect to which we are unable to obtain a refund from the relevant tax authorities. If our Israeli, French and Irish subsidiaries were to no longer qualify for these lower tax rates or if the applicable tax laws were rescinded or changed, our operating results could be materially adversely affected. A mix of our revenues in each of these locations may change the mix of our taxable income, and as a result, our overall tax rate may increase, as we encountered in 2021, specifically due to higher taxes in France, or in the third quarter of 2022, due to our recording a $15.6 million expense as a result of a valuation allowance for certain deferred tax assets in Israel.
U.S. tax regulations are also implicated by our international operations. For example, certain of our taxes may be "double taxed" in both foreign jurisdictions and the U.S., including with respect to our taxes on our Irish and Israeli interest income. While we have elected to account for global intangible low-taxed income (GILTI) as a current-period expense when incurred, legislation and clarifying guidance are expected to continue to be issued by the U.S. Treasury Department and various states in future periods, which could have a material adverse impact on the value of our U.S. deferred tax assets, result in significant changes to currently computed income tax liabilities for past and current tax periods, and increase our future U.S. tax expense. We could also incur significant additional tax expenses as a result of moving off-shore cash to our U.S. entity. Out of total cash, cash equivalents, bank deposits and marketable securities of $163.6 million at year end 2024, $135.1 million was held by our foreign subsidiaries, with only $28.5 million held in the U.S., which could make capital expenditures to expand operations in the U.S., or our conducting strategic transactions in the U.S., more expensive. In addition, beginning in our fiscal year 2022, the Tax Cuts and Jobs Act of 2017 eliminates the option to deduct research and development expenditures in the year incurred, requiring amortization in accordance with Internal Revenue Code (IRC) Section 174. If this requirement is not repealed or otherwise modified, it will potentially materially increase our effective tax rate and reduce our operating cash flows in future years.
Furthermore, several countries, including the U.S. and Ireland, as well as the Organization for Economic Cooperation and Development have reached agreement on a global minimum tax initiative. Many countries are also actively considering changes to existing tax laws or have proposed or enacted new laws that could increase our tax obligations in countries where we do business or cause us to change the way we operate our business.
Finally, our determination of our tax liability in the U.S. and other jurisdictions, including our intercompany transfer pricing, is subject to review by applicable domestic and foreign tax authorities. Although we believe that our tax estimates are reasonable, due to the complexity of our corporate structure, the multiple intercompany transactions and the various tax regimes, we cannot assure you that a tax audit or tax dispute to which we may be subject will result in a favorable outcome for us. If taxing authorities do not accept our tax positions and impose higher tax rates on our foreign operations, our overall tax expenses could increase.